LIBRARY 

OF    THE 

UNIVERSITY  OF  CALIFORNIA. 
Class 


GENERM- 


Hardening,  Tempering,  flnneaiing 

AND 

FORGING   OF   STEEL 

A  TREATISE  ON  THE  PRACTICAL  TREATMENT  AND 
WORKING  OF  HIGH  AND  LOW  GRADE  STEEL 

COMPRISING 

THE    SELECTION   AND    IDENTIFICATION   OF   STEEL,   THE   MOST 
MODERN  AND  APPROVED    HEATING,    HARDENING,    TEMPER- 
ING,   ANNEALING    AND     FORGING    PROCESSES,    THE     USE 
OF     GAS     BLAST     FORGES,     HEATING     MACHINES     AND 
FURNACES,   THE    ANNEALING   AND    MANUFACTURING 
OF   MALLEABLE  IRON,   THE   TREATMENT  AND    USE 
OF      SELF-HARDENING      STEEL,     WITH      SPECIAL 
REFERENCE    TO    CASEHARDENING   PROCESSES, 
THE  HARDENING  AND   TEMPERING  OF  MILL- 
ING CUTTERS  AND  PRESS  TOOLS,  THE   USE 
OF     MACHINERY    STEEL    FOR    CUTTING 
TOOLS,  FORGING  AND  WELDING,  HIGH 
GRADE  STEEL  FORCINGS  IN  AMERICA, 
FORGING    OF     HOLLOW     SHAFTS, 
DROP-FORGING,      AND      GRIND- 
ING   PROCESSES    FOR    TOOLS 
AND     MACHINE     PARTS 


JOSEPH    V.    WOODWORTH 

Author  of  "Dies,   Their   Construction  and    Use 

Illustrated  by  201  Engravings 


NORMAN    W.    HENLEY    &    CO. 

132  NASSAU  STREET 

NEW  YORK 

1903 


COPYRIGHTED,    1902, 
BY 

NORMAN  W.  HENLEY  &  Co. 


MACGOWAN  &  SLIPPER 

PRINTERS 

30  Beekman  Street 

New  York 

U.S.A. 


TO 

GEORGE    WOODWORTH 

MY    FATHER,     FRIEND    AND    FEI<I,OW     WORKER,     TO    WHOSE    I<OVE, 

AFFECTION   AND   ENCOURAGEMENT   I  OWE   MORE   THAN 

CAN    EVER    BE    REPAID,     THIS    BOOK    IS 

AFFECTIONATELY   DEDICATED 


103848 


PREFACE. 


In  preparing  this  treatise  the  author  has  had  as  an  incitement 
the  knowledge  that  there  was  very  little  information  to  be  had  on 
the  treatment  and  working  of  steel  of  practical  value  to  the  gen- 
eral mechanic.  For  this  reason  he  is  convinced  that  a  practical 
book  on  the  treatment  and  working  of  the  metal  as  modern  de- 
mands necessitate,  that  is,  in  regard  to  heating,  annealing,  forg- 
ing, hardening  and  tempering  processes,  cannot  fail  to>  prove  of 
interest  and  value  to  all  mechanics  who  use  tools  or  who  are  in 
any  way  engaged  in  the  working  of  metals. 

When  the  fact  is  considered  that  tools  made  from  the  best 
grades  of  steel  will  not  perform  the  work  required  unless  they 
have  been  treated  properly  during  the  various  heating  processes, 
the  value  of  a  knowledge  of  the  most  satisfactory  and  approved 
arrangements  and  methods  to  the  mechanic  is  at  once  apparent. 

With  the  object  in  view  of  giving  to  practical  men  a  book 
treating  and  presenting  this  paramount  subject  in  a  clear,  con- 
cise and  practical  manner,  the  author  has  drawn  upon  a  personal 
experience  of  many  years,  gathered  all  the  information  obtain- 
able, eliminating  all  unnecessary  and  obsolete  matter,  and  added 
all  that  is  approved,  up-to-date  and  authentic. 

In  regard  to  originality  we  lay  claim  to  very  little,  for,  al- 
though the  facts  contained  in  a  large  number  of  the  items  have 
been  gained  through  years  of  experience  at  the  forge,  bench  and 
machine,  we  are  indebted  to  others  for  a  greater  portion,  and 
merely  claim  to  have,  as  a  great  poet  has  said,  "gathered  the 
fruits  of  other  men's  labors  and  bound  them  with  our  own  string.'' 
To  the  technical  journals,  notably  the  American  Machinist,  Ma- 
chinery, the  Iron  Age,  the  Scientific  American,  the  Age  of  Steel, 
Modern  Machinery,  and  Shop  Talk;  to  master  mechanics  of 
well-known  shops,  to  many  American  machine-tool  and  tool  and 
die  making  concerns,  and  to  individual  fellow  craftsmen,  the 
author  takes  pleasure  in  herein  acknowledging  his  indebtedness, 
with  thanks  for  a  laree  number  of  facts  contained  in  this  volume. 

The  chapters  on  Miscellaneous  Methods,  Tables, and  on  Emery 


6  PREFACE. 

Wheel  Grinding  of  tools,  have  been  thought  so  near  akin  to  the 
general  subject  of  this  work,  that  they  have  been  given  a  place  and 
will  be  found  valuable  to  the  tool  maker  and  general  machinist. 

Much  valuable  information  was  furnished,  and  many  of  the 
engravings  which  were  used  to  illustrate  the  work  were  kindly 
loaned  to  the  author  by  the  following  named  firms :  Cincinnati 
Milling  Machine  Company,  Cincinnati,  Ohio;  American  Gas  Fur- 
nace Company,  New  York,  N.  Y. ;  Faneuil  Watch  Tool  Com- 
pany, Brighton,  Boston,  Mass. ;  Standard  Tool  Company,  Cleve- 
land, Ohio;  J.  H.  Williams  Company,  Brooklyn,  N.  Y. ;  the 
Rogers  &  Hubbard  Company,  Middletown,  Conn. ;  Pratt  & 
Whitney,  Hartford,  Conn. ;  Garvin  Machine  Company,  New 
York,  N.  Y. ;  Armstrong  Brothers  Tool  Company,  Chicago,  111. ; 
Chicago  Flexible  Shaft  Company,  Chicago,  111.;  Nicholson  File 
Company,  Providence,  R.  I.;  E.  W.  Bliss  Company,  Brooklyn, 
N.  Y. 

Although  the  writer  is  aware  that  his  efforts  will  meet  with 
criticism  from  those  who  may  feel  that  it  is  not  technical  enough, 
or  that  some  particular  process  or  special  method  has  been  ig- 
nored, he  is  pleased  to  assure  the  reader  that  all  that  it  does  con- 
tain has  been  authenticated,  and  he  is  convinced  that  the 
majority  will  find  in  its  pages  information  which  will  assist  them 
in  overcoming  trials  and  difficulties  met  with  in  the  working  of 
this  "truly  wondrous  metal." 

Brooklyn,  N.  Y.,  December,  1902. 

JOSEPH  V.  WOODWORTH. 


CONTENTS. 


CHAPTER  I. 

STEEL — ITS    SELECTION    AND    IDENTIFICATION — STEEL    FOR    VARIOUS    PURPOSES—- 
THE   TREATMENT    OF    WELL-KNOWN    BRANDS    OF    STEEL 
— THE    EFFECTS    OF    HEAT. 

Selection  and  Identification  of  Steel — Steel  for  Different  Purposes 
—Die  Steel— Steel  Die  Forgings— The  Treatment  of  High-Car- 
bon Steels — Experimental  Treatment — The  Treatment  and 
Working  of  Well-known  Brands  of  Tool  Steel — Heating  for 
Forging — Heating  for  Hardening — Treatment  of  High-speed 
Self-hardening  Steels — Annealed  Die  and  Tool  Steel — Treat- 
ment of  Annealed.  Die  and  Tool  Steel — Treatment  of  Air-hard- 
ening Steel — The  Best  Steel  for  Tools — Testing  Tool  Steel — 
The  Grain  of  Steel — Testing  for  Toughness — Economy  in  -Test- 
ing Steel  Before  Using — Decarbonized  Steel  Surfaces — How  to 
Know  Tool  Steel  from  Mild  Steel — Tool  Holders  and  Tools — 
Self-hardening  Steel  Cutting  Tools— Speeds  for  Cutting  Tools 
— Cutting  and  Durability  Qualities  of  Steel — Judgment,  Experi- 
ence, and  Perception  in  the  Working  of  Steel — The  First  Effects 
of  Heat — Unequal  Expansion — Heat  Effects  on  Clay — 
The  Amount  of  Force  Exerted  in  Expansion  or  Contraction — 
The  Second  Effect  of  Heat — Table  of  Expansion  from  32  Deg. 
F.  to  212  Deg.  F. — Kinds  of  Steel  Produced  in  America  by 
the  Crucible  and  Open-hearth  Processes. 13  to  35 

CHAPTER  II. 

ANNEALING    PROCESSES — THE    TERMS    ANNEALING,     HARDENING,    AND    TEMPER- 
ING    DEFINED THE    ANNEALING     OF     MALLEABLE     CASTINGS. 

The  Terms  Defined — How  to  Thoroughly  Anneal  High-grade  Tool 
Steel  Parts — The  Proper  Heat  for  Annealing — Annealing  in 
the  Charcoal  Fire — Good  Steel  for  Good  Tools — Annealing — 
An  Annealing  Box  for  Small  Parts — Water  Annealing — The 
Effect  of  the  Water  Anneal — The  Annealing  of  Tap  Steel — 
Reannealing  Tap  Blanks — How  to  Heat  for  Annealing — An- 
nealing a  Small  Quantity  of  Steel — Annealing  Steel  in  the 
Open  Fire — Quick  Methods  for  Softening  Steel — To  Anneal 
Doubtful  Steel — Annealing  Chilled  Cast-iron  Dies  for  Drilling 
— Annealing  White  or  Silver  Iron — The  Annealing  of  Malle- 


CONTENTS. 

able  Castings  and  the  Manufacture  of  Malleable-iron  Machine 
Parts — The  Foundry,  and  Preparation  of  the  Castings — An- 
nealing Furnaces — Packing  the  Castings — Different  Methods 
of  Packing  Castings  in  Pots — Annealing,  Straightening  and 
Finishing  Malleable  Castings — Heating  the  Annealing  O'vens — 
General  Matter  Relative  to  Malleable-iron  Manufacturing.  ..  .36  to  49 


CHAPTER  III. 

THE     HEATING     AND     COOLING     OF     STEEL — LOCATION     OF     HEATING     ARRANGE- 
MENTS  THE  USE  OF  GAS  BLAST  FURNACES  AND   HEATING   MACHINES 

— TOUGH    STEEL    AND    HARD    STEEL — THE    DIFFERENCE. 

The  Heating  and  Cooling  of  Steel — Proper  Equipment  for  Harden- 
ing and  Tempering — Points  to  be  Remembered — The  Loca- 
tion of  the  Heating  Furnace — The  Use  of  Gas-blast  Furnaces 
and  Heating  Machines — Gas-blast  Forges — Their  Use — Combi- 
nation Gas  Furnace  for  General  Machine-shop  Work — Gas 
Forge  for  Small  Work — Gas  Forge  for  Heating  Drop  Forgings 
— Air-tempering  Furnace — Gas  Forge  for  Knife  and  Shear 
Blades — Bench  Forge — Oven  Furnaces  for  Annealing  and 
Hardening — Case-hardening  Furnaces — Heating-machine  for 
Hardening  the  Edges  of  Mower  Blades — Heating-machine  for 
Hardening  Cones  and  Shells — Heating-machine  with  Revolving 
Trays — Heating-machine  for  Small  Parts — Barrel  Heating-ma- 
chine for  Hardening  and  Tempering  Balls,  Saw  Teeth,  Screws, 
etc — Construction  and  Operation  of  Barrel  Heating-machine — 
Heating-machine  for  Tempering  and  Coloring  Steel — Circular 
Annealing  and  Hardening  Furnace — Oil  Tempering  Furnaces 
— Automatic  Heating-machine  for  Hardening  Chain — Cylindri- 
cal Case-hardening  Furnaces — Lead  Hardening  Furnace — 
Melting  Pots — Cyanide  Hardening  Furnaces — Regular  Sizes  of 
Muffles — Muffle  Furnaces — Tough  Steel  and  Hard  Steel — the 
Difference  50  to  94 


CHAPTER  IV. 

THE     HARDENING    OF     STEEL — HARDENING    IN     WATER,    BRINE,    OIL,     AND     SOLU- 
TIONS— SPECIAL    PROCESSES    FOR    SPECIAL    STEEL. 

Judgment  and  Carefulness  in  Hardening — Successful  Hardening — 
Different  Quenching  Baths — Their  Effect  on  Steel — General 
Directions  and  Rules  for  the  Hardening  of  Steel — Distortion 
Through  Uneven  Heating — The  Hardening  Fire  and  the  Heat — 
Quenching  for  Hardening — The  Hardening  of  Long  Slender 
Tools — Hardening  Small  Parts  and  Long  Thin  Parts — Harden- 
ing in  Solutions — Heating  in  Hot  Lead  for  Hardening — Hard- 
ening Metal  Saws — Mixture  to  Prevent  Lead  from  Sticking 


CONTENTS.  9 

when  Heating  for  Hardening — Hardening  Long  Taper  Ream- 
ers— The  Use  of  Clay  in  Hardening — Special  Instructions  for 
Hardening  and  Tempering — Hardening  and  Tempering  Round- 
thread  Dies — Hardening  Bushings,  Shell  Reamers,  Hobs,  etc. — 
Hardening  and  Tempering  Collet  Spring  Chucks— The  Taylor- 
White  Process  for  Treating  Steel 95  to  116 

CHAPTER  V. 

TEMPERING BY   COLORS — IN    OIL ON    HOT    PLATES — BY   THERMOMETER — IN    HOT 

WATER — IN    THE    SAND   BATH — BY    SPECIAL    METHODS. 

Tempering — Tempering  in  the  Sand  Bath — The  Effects  of  Slow 
Heating  and  Tempering — Tempering  in  Oil — Hardening  and 
Tempering  Springs — Blazing  off  Springs — Tempering  Rock 
Drills  in  Crude  Oil— Hardening  and  Tempering  Mill 
Picks — Straightening  Hardened  Pieces  that  have  Warped 
—Tempering  Thin  Articles — Tempering  in  the  Charcoal 
Flame — Tempering  Wood-planer  Knives — Tempering  Swords 
and  Cutlasses — Drawing  Polished  Steel  Articles  to  a 
Straw  Color  or  Blue — Tempering  Solutions — Table  of  Melt- 
ing Points  of  Solids — Table  of  Tempers  to  Which  Tools 
should  be  Drawn— Table  of  Suitable  Temperatures  for  An- 
nealing, Working  and  Hardening— Table  of  Suitable  Tem- 
peratures for  Case-hardening,  Core  Ovens,  Drying  Kilns,  Bak- 
ing Enamels  and  Vulcanizing  Rubber — Table  of  Temper  Colors 
of  Steel  117  to  128 

CHAPTER  VI. 

CASE-HARDENING    PROCESSES — THE    USE    OF    MACHINERY    STEEL    FOR    CUTTING 
TOOLS   AND  THE   TREATMENT  OF  IT. 

The  Use  of  Machine  Steel  for  Press  Tools— Outfit  for  Fine- 
Grain  Case-hardening — Packing  and  Heating  the  Work — Case- 
hardening  Cutting  Tools — How  to  Case-harden,  Color  and  An- 
neal with  Granulated  Raw  Bone — To  Case-harden  Without 
Colors — Hardening  Extra-heavy  Work — Hardening  Drawbridge 
Disc  and  Similar  Work — Hardening  Five-inch  Thrust  Bearing 
Rings — How  to  Harden  Rolls,  Leaving  Tenons  Soft  for  Rivet- 
ing— How  to  Case-harden  Malleable  Iron — How  to  Use  Old 
Bone — Bone  and  Charcoal — Using  the  Tell-tale — Obtaining  Col- 
ors with  Granulated  Raw  Bone — Preparation  of  the  Work — 
Charring  the  Bone — Packing  the  Work — Heating — The  Bath — 
How  to  Dump  the  Work — Cleaning  the  Work — Colors  from  a 
Light  Straw  to  a  Deep  Blue — Directions  for  Annealing  with 
Granulated  Raw  Bone — Cooling — Annealing  Low-carbon  Steel 
Bars — Annealing  Iron  Castings — Case-hardening  with  Cyanide 
of  Potassium — Accurate  Sectional  Case-hardening — To  Produce 


IO  CONTENTS. 

Fine-grained  Hardened  Machine-steel  Parts — Case-hardening 
the  Ends  of  Steel  Rails — Very  Deep  Case-hardening — To  Case- 
harden  Small  Iron  Parts — To  Case-harden  with  Charcoal — 
Moxon's  Method  of  Case-hardening — A  Case-hardening  Mixture 
for  Iron — A  Case-hardening  Paste — Case-hardening  Polished 
Parts — Case-hardening  as  it  should  be  Understood 129  to  142 

CHAPTER  VII. 

HARDENING     AND     TEMPERING      MILLING     CUTTERS     AND     SIMILAR     TOOLS. 

Hardening  Milling  Cutters  in  the  Open  Fire — Hardening  Large 
Milling  Cutters — Hardening  and  Tempering  Milling  Cutters  in 
Water  and  Oil — Advantages  of  the  Method — Hardening  V- 
shaped  Milling  Cutters — Hardening  Hollow  Mills — Milling 
Cutters  143  to  155 

CHAPTER  VIII. 

HARDENING,    TEMPERING    AND    STRAIGHTENING    ALL    KINDS    OF     SMALL    TOOLS. 

Hardening  Ring  Gages — Dipping  Small  Tools  when  Hardening — 
Dipping  Half-round  Reamers  or  "Gun"  Reamers  when  Hard- 
ening— Dipping  Fluted  Reamers  when  Hardening — Straighten- 
ing Long  Tools  which  have  Warped  in  Hardening — Hardening 
Very  Thin  Tools  so  as  to  Prevent  Warping — Warping  of 
Long  Tools  in  Hardening — Temperature  Tell-tales  for  Use 
in  Heating  Steel — Working  Steel  for  Tools — Hardening  Small 
Saws — Hardening  Cutter-bits — Hardening  Mixture  for  General 
Smith  Work — Tempering  Flat  Drills  for  Hard  Stock — To  Tem- 
per Gravers — To  Temper  Old  Files. — Hardening  and  Tempering 
Small  Taps,  Knives,  Springs,  etc. — Tempering  Small  Spiral 
Springs — To  Draw  Small  Steel  Parts  to  a  Blue 156  to  161 

CHAPTER  IX. 

THE  HARDENING  AND  TEMPERING   OF  DIES   AND  ALL   KINDS   OF  PRESS   TOOLS  FOR 
THE    WORKING    OF    SHEET    METAL. 

The  Hardening  and  Tempering  of  Press  Tools— Hard  or  Soft 
Punches  and  Dies — Hardening  and  Tempering  Drop  Dies — 
How  to  Harden  Large  Ring  Dies— How  to  Harden  a  Long 
Punch  so  as  to  Prevent  Warping — Steel  for  Small  Punches 
—Hardening  a  Blanking  Die— Cracks  in  Dies— Their  Cause 
— Hardening  the  Walls  of  a  Round  Die — Reannealing  a 
Punch,  or  a  Die  Blank — Warping  of  Long  Punches  in 
Hardening— Hardening  Very  Small  Punches— Tempering 
Small  Punches — Hardening  Fluids  for  Dies — Hardening  Thick 


CONTENTS.  II 

Round  Dies — Hardening  Poor  Die  Steel — Tempering  a  Combi- 
nation Cutting  and  Drawing  Punch — Hardening  and  Tempering 
a  Split  Gang  Punch — Hardening  and  Tempering  Large  "Cut- 
ting" or  "Blanking"  Dies 162  to  174 

CHAPTER  X. 

FORGING   AND   WELDING — HOW    TO    ACCOMPLISH    SATISFACTORY    RESULTS    IN 
T::E    FORGING    AND    WELDING    OF    STEEL    AND    IRON — DROP    FORGING. 

Welding  Heats — A  Good  Welding  Flux  for  Steel — Heating  Steel 
for  Forging — Steel  for  Tools  which  Require  to  be  Forged — 
High-grade  Steel  Forgings  in  America — How  Hollow  Shafts 
are  Forged — Difficulties  Encountered  in  Introducing  High- 
grade  Forgings — Cold  Crystallization  does  not  Occur — Tests 
of  Steel  under  Repeated  Stresses — Charcoal — Welding  Powder 
for  Iron  and  Steel — To  Make  Edged  Tools  from  Cast  Steel  and 
Iron— To  Weld  Cast  Iron — Welding  Composition  for  Cast  Steel — 
How  to  Restore  Overheated  Steel — Composition  to  Toughen 
Steel — Pointer — To  Weld  Buggy  Springs — A  French  Welding 
Flux — Compound  for  Welding  Steel — Fluxes  for  Soldering  and 
Welding — Substitute  for  Borax  in  Welding — Drop-forging — 
Directions  for  Setting  up  Forging  Drop-Hammers — Government 
Use  of  Nickel  Steel  for  Forgings 175  to  194 

CHAPTER  XI. 

MISCELLANEOUS     METHODS,     PROCESSES,     KINKS,     POINTERS     AND     TABLES     FOR 
USE    IN    METAL    WORKING. 

Increasing  the  Size  of  a  Reamer  when  Worn — To  Case-harden 
Cast  Iron — Improved  Soldering  and  Tinning  Acid — Rules  for 
Calculating  Speed — Lubricant  for  Water  Cuts — Babbitting — Lay- 
ing out  Work — Lubricant  for  Working  Aluminum — To  Prevent 
Rust — Lubricant  for  Drilling  Hard  Steel — Coppering  Polished 
Steel  Surfaces— To  Blue  Steel  Without  Heating— To  Remove 
Scale  from  Steel — To  Distinguish  Wrought  Iron  and  Cast 
Iron  from  Steel — Anti-friction  Alloy  for  Journal  Boxes — Solder 
for  Aluminum — Case-hardening  with  Kerosene — Case-harden- 
ing Cups  and  Cones — Drills — Reamer  Practice — Reamers  and 
Reaming — Number  of  Teeth  Generally  Milled  in  Reamers — 
Grinding  Twist  Drills — Circular  Forming  Tools — Plain  Form- 
ing Tools — Facing — Counterboring — Soldering — Lacquer  for 
Brass  Articles — Removing  Rust  from  Polished  Steel  and  Iron — 
Miscellaneous  Information— Useful  Information— Table  of 
Decimal  Equivalents  of  Millimeters  and  Fractions  of  Milli- 
meters— Table  of  Decimal  Equivalents  of  Parts  of  an  Inch — 
Table  of  Constants  for  Finding  Diameter  at  Bottom  of  Thread — 


12  CONTENTS. 

—Table  of  English  or  American  (U.  S.)  Equivalent  Meas- 
ures— Table  of  Weights  and  Areas  of  Round,  Square  and 
Hexagon  Steel — Table  of  Weights  of  Iron  and  Steel  Sheets 
—Table  of  Weights  of  Square  and  Round  Bars  of  Wrought 
Iron  in  Pounds  per  Lineal  Foot — United  States  Weights  and 
Measures — Table  of  Tap  Drills  for  Machine  Screw  Taps — 
Table  of  Size  of  Drills  for  Standard  Pipe  Taps — Table  of 
Different  Standards  for  Wire  Gage  used  in  U.  S. — Table  of 
United  States  Standard  Screw  Threads — Formulas  for  Sharp 
V  Thread,  United  States  Standard  Thread,  Whitworth 
Standard  Thread — The  Acme  Standard  Thread — Table  of 
Thread  Parts — Table  of  Average  Cutting  Speeds  for  Drills — 
Table  of  Cutting  Speeds — Horse  Power  of  Belts — Cutting 
Lubricant 195  to  225 

CHAPTER  XII. 

GRINDING — THE      ACCURATE    AND      RAPID      GRINDING      OF      TOOLS      AND      SMALL 
MACHINE     PARTS — EMERY     WHEELS — THEIR     USE. 

Cutter  and  Tool  Grinding — Prominent  Features — Grinding  a  Spiral 
Mill — Grinding  Angular  Cutters — Grinding  Side-milling  Cut- 
ters— Grinding  Milling  Cutters  or  Metal  Slitting  Saws  from  8 
to  12  Inches  in  Diameter— Gear  Cutter  Grinding— Grinding 
Formed  Cutters — How  to  Grind  a  Worm-wheel  Hob — Grinding 
a  Hand  Reamer — Grinding  a  Taper  Reamer — How  to  Grind  a 
Hardened  Drilling  Jig  Bushing — How  to  Grind  a  Taper  Spindle 
—How  to  Grind  a  Slitting  Knife  with  Beveled  Edges— Internal 
Grinding— Grinding  a  Straight  Edge— Grinding  a  Shear  Plate 
— How  to  Grind  a  Die  Blank'  to  the  Required  Angle — Grinding 
a  Formed  Tool  on  its  Face— The  Emery  Wheel  Used  as  a 
Metal  Slitting  Saw— Grinding  a  Gage  to  a  Given  Dimension- 
Attachment  for  Surface  Grinding— How  to  Grind  Milling  Cut- 
ters and  Metal  'Slitting  Saws  Straight  or  Concave— General 
Directions— Diamond  Tool  Holder— A  Small  Cutter  Grinder- 
Illustration  Showing  Various  Work  Performed  on  a  Different 
Type  of  Universal  Cutter  and  Tool  Grinder— Attachments 
which  are  Used  on  the  Machine— Emery  Wheels— Their  Use- 
Approximate  Speeds  for  Emery  and  Polishing  Wheels— Table 
of  Articles  Made  from  Crucible  Steel,  Giving  About  Percent- 
age of  Carbon  they  should  Contain 226  to  275 


CHAPTER  I. 

STEEL,    ITS    SELECTION    AND    IDENTIFICATION STEEL    FOR    VARIOUS 

PURPOSES THE   TREATMENT  AND  WORKING  OF   WELL-KNOWN 

BRANDS    OF    TOOL    STEEL THE    EFFECTS    OF    HEAT. 

Selection  and  Identification  of  Steel. 

It  would  be  a  fine  thing  if  we  could  start  with  giving  the 
name  of  a  brand  of  tool  steel  which  would  answer  for  all  kinds 
of  tools ;  would  harden  without  trouble,  and  temper  evenly  in  the 
"good  old-fashioned  way."  But  as  we  cannot  do  this,  we  can 
only  hope  that  some  day  a  steel  which  will  answer  for  all  purposes 
will  be  produced ;  until  then  we  must  rest  content  with  what 
we  have  got  and  through  experience  learn  of  the  best  brand  of 
steel  to  use  for  a  given  purpose. 

There  is  absolutely  no  economy  in-  purchasing  tool  steel  be- 
cause it  is  cheap.  In  fact,  economy  in  steel  can  only  be  obtained 
by  purchasing  a  grade  of  steel  which  is  uniformly  of  the  best 
quality,  as  its  superior  lasting  quality,  and  its  ability  to  retain  a 
cutting  edge  for  long  periods  make  it  the  cheapest  and  most 
satisfactory  in  the  end.  Such  steel  costs  more  in  the  beginning, 
but  then  cheap  steel  has  often  cost  almost  "its  weight  in  gold" 
before  it  was  thrown  out.  Almost  every  machinist,  who  has 
worked  in  any  number  of  shops,  has  had  experience  with  the 
different  grades  and  brands  of  steel  for  tools,  and  he  knows  that 
cheap  steel  is  expensive. 

As  the  first  thing  necessary  to  allow  of  successful  metal  work- 
ing, in  any  branch  of  the  machinist's  art  is  good  steel,  too  much 
attention  cannot  be  given  to  the  selection  of  a  steel  of  uniform 
quality.  This  can  only  be  brought  about  through  experience  in 
working  and  using  the  different  brands  for  purposes  required, 
and  when  a  grade  has  been  procured  which  can  be  handled  suc- 
cessfully and  gives  satisfaction  in  use,  stick  to  it  and  never 
change  until  you  are  convinced  that  you  have  struck  a  better  one. 

After  having  selected  the  brands  and  grades  of  steel  that  are 
suited  for  the  classes  of  work  required,  adopt  some  method  of 
marking  each  separate  brand  so  the  workmen  will  be  able  to 
recognize  them  without  the  fire  and  water  test.  The  best  way 
to  insure  against  difficulty  arising  from  the  mistakes  in  using 
the  wrong  brand  of  steel  is  to  have  each  brand  or  grade  striped 


14  HARDENING,    TEMPERING    AND    ANNEALING. 

with  a  different  color  paint.  Have  some  one  stripe  the  steels 
along"  their  entire  length,  as  soon  as  received,  and  either  place  each 
brand  in  a  separate  rack  with  the  name  of  the  steel  on  it,  or  have 
a  board  hanging  near  the  steel  rack  with  short  stripes  of  paint  of 
the  colors  used  and  the  name  of  each  brand  next  the  stripe  de- 
noting it.  In  this  manner  the  brand  of  steel  desired  can  be  found 
in  a  moment  with  the  certainty  that  it  will  be  the  right  brand. 

Steel  for  Different  Purposes. 

For  small  reamers,  taps,  small  round  punches,  which  are  to 
cut  at  slow  speeds,  and  other  tools  of  a  like  nature,  use  drill  rod, 
not  necessarily  Stubs — any  good  American  drill  rod  will  answer 
as  well.  Never  use  a  very  high  carbon  steel  for  taps  and  dies  or 
other  threading  tools. 

Die  Steel. 

In  no  branch  of  the  machinist's  art  should  more  attention  be 
given  to  the  importance  of  the  proper  selection  of  steel  than  in 
die-making,  as  the  working  qualities  of  the  tools  when  finished 
and  their  efficiency  depend  upon  this  more  than  anything  else. 

When  ordering  steel  which  is  to  be  used  for  dies  be  sure  to 
specify  that  annealed  steel  is  wanted,  as  the  saving  of  time  and 
labor  in  the  working  of  it,  and  the  certainty  of  the  results  in  the 
hardening  and  tempering  of  it  after  the  re-annealing,  will  be  a 
source  of  gratification  to  the  mechanic.  When  these  results 
are  considered  the  slight  extra  cost  of  annealed  steel  is  insig- 
nificant. 

As  to  the  grade  of  steel  to  use  for  dies,  be  sure  to  get  a  good 
grade,  and  as  there  are  several  brands  of  steel  on  the  market 
which  are  used  principally  for  dies  and  punches  no  difficulty 
should  be  experienced  in  procuring  a  grade  or  brand  which  will 
prove  suitable  for  any  special  class  of  sheet-metal  work. 

Steel  Die  Forgings. 

When  steel  forgings  are  required,  from  which  dies  are  to 
be  made,  the  job  should  be  given  to  a  smith  who  understands 
this  branch  of  his  art,  as  in  order  for  the  forgings  to  machine 
well  and  allow  of  being  hardened  and  tempered  as  desired,  so 
that  the  finished  tools  will  accomplish  the  required  results,  the 
smith  must  understand  such  work.  As  too  high  a  welding  heat, 
a  raw  weld  joint,  rapid  cooling  of  the  forging  and  other  effects 


STEEL,    ITS   SELECTION    AND   IDENTIFICATION  15 

of  carelessness  are  often  responsible  for  the  spoiling  of  an  ex- 
pensive tool  in  hardening,  a  good  smith  is  necessary  for  such 
work. 

The  Treatment  of  High-Carbon  Steel. 

The  treatment  of  high-grade  tool  steel  is  a  subject  which  has 
been  discussed  often  and  to  great  length,  but  it  is  one  of  the 
greatest  importance  to  steel  users  and  too  much  cannot  be  written 
on  it.  How  often  has  a  piece  of  steel  been  condemned  as  being 
of  inferior  quality  when  the  fault  lay,  not  in  the  steel,  but  in 
those  who  had  selected  and  used  it.  The  causes  of  failure  in 
using  a  high-grade  steel  are  numerous.  Often  the  proportion  of 
carbon  is  not  right  for  t{ie  purpose  required ;  then  again,  the  steel 
is  overheated  when  forging,  annealing,  hardening  or  tempering, 
most  frequently  in  the  tempering  process,  which  in  high-grade 
steel  is  a  delicate  operation  requiring  knowledge,  skill  and  ex- 
perience. 

It  is  impossible  for  a  machinist  to  determine  the  correct  har- 
dening process  for  high-carbon  steels  unless  he  is  familiar  with 
the  characteristic  appearance  of  fractures  of  a  specimen  which 
has  been  treated  properly.  Any  operator  who  has  worked  steel 
of  good  quality  and  is  familiar  with  the  appearance  of  the  differ- 
ent fractures  has  no  difficulty  in  'avoiding  injurious  treatment 
during  the  hardening  process.  It  is,  however,  impossible  to 
describe  the  appearance  of  fractures  of  high-grade  steel  of  various 
hardness  in  a  manner  to  allow  of  their  being  understood  by 
mechanics  in  general,  or  in  fact  to  be  practically  useful  to  any 
great  extent,  this  knowledge  only  being  communicated  to  the 
operator  through  experience. 

Experimental  Treatment. 

Some  idea  may  be  gained  of  the  great  and  varied  alterations 
produced  in  high-carbon  steel  through  the  different  methods  of 
hardening  by  a  description  of  a  test  experiment.  If  a  forged  or 
rolled  bar  of  high-grade  steel  is  nicked  at  a  number  of  places 
equidistant  apart  along  its  entire  length  a  suitable  specimen  will 
be  obtained  for  experimental  purposes.  Place  one  end  of  the  bar 
in  the  fire  far  enough  to  allow  of  heating  the  first  section  up  to 
the  nick  to  a  white  heat.  Thus  the  rest  of  the  bar,  being  out  of 
the  fire,  will  be  heated  to  a  decreasing  temperature  toward  the 
other  end.  As  soon  as  the  first  section  is  at  a  white  heat,  thus 
burning  the  steel,  through  its  being  of  a  high  carbon  percentage. 


i6 


HARDENING,    TEMPERING    AND    ANNEALING. 


and  the  heat  of  the  remainder  of  the  bar  becomes  a  dull  red,  take 
the  bar  from  the  fire  and  quench  it  instantly  into  a  cold  water  bath. 
Leave  the  metal  in  the  bath  until  cold  and  then  remove  and  dry 
it.  By  testing  with  a  file  the  first  section  will,  of  course,  prove 


the  hardest,  and  the  intermediate  sections  of  degrees  of  hardness 
passing  from  the  softest  to  the  hardest.  Thus  the  conditions  of 
the  different  sections,  when  broken  apart  at  the  fracture  points, 
will  show  the  operator  the  results  in  the  steel  when  hardened  at  a 
given  temperature.  On  breaking  the  pieces  at  each  neck  it  will  be 


STEEL,    ITS   SELECTION   AND   IDENTIFICATION  I/ 

noticed  that  very  considerable  changes  have  taken  place  in  the 
grain  of  the  metal.  The  first  piece,  which  has  been  burnt,  through 
heating  to  a  white,  has  a  very  open  and  crystallized  fracture, 
while  the  succeeding  pieces  are  of  a  closer  grain  as  they  approach 


the  end.  Thus  the  selected  piece  or  section,  which  has  been 
subjected  to  the  proper  degree  of  heat  in  accordance  with  the 
carbon  percentage  of  the  steel,  will  be  found  to  possess  that  per- 
fectly even  grain  and  velvety  appearance  which  is  looked  upon 
by  all  experienced  tool  steel  users  as  a  condition  to  be  prized  in 


iS  HARDENING,    TEMPERING    AND    ANNEALING. 

hardened  steel.  The  first  pieces  will  probably  show  cracks  from 
being  quenched  at  too  high  a  temperature,  while  those  at  the  other 
end  will  be  hardened  throughout  as  desired.  Thus,  through  an 
experiment  of  this  kind,  we  learn  that  in  order  to  make  a  piece  of 
steel  hard  and  tough  the  temperature  must  be  sufficiently  high 
to  allow  of  hardening  it  through,  but  not  high  enough  to  open 
the  grain. 

The  Treatment  and  Working  of  Well-Known  Brands  of  Tool 

Steel 

The  brands  of  tool  steel  in  general  use  throughout  the  United 
States  and  the  ones  which  are  best  known  and  understood  among 
steel  users  are  Jessop's,  Hobson's,  Crescent,  Styrain,  Howe- 
Brown,  Sanderson's,  Capital  and  a  number  of  self-hardening 
brands.  In  the  following  we  give  descriptions  for  the  working 
of  the  different  brands  of  which  we  have  been  able  to  obtain 
data.  For  all  high-grade  steels  the  directions  will  prove  satis- 
factory. Figs,  i  and  2  show  sections  of  shapes  and  sizes  of  file 
steel. 

Heating  for  Forging. 

For  Jessop's  steels  heating  for  forging  is,  in  its  way,  quite 
as  important  as  heating  for  hardening;  care  and  uniformity  in 
the  application  of  the  heat  in  the  first  instance  is  very  essential. 
Should  the  steel  be  overheated  in  this  process  no  amount  of  care 
afterward  will  restore  the  steel  to  its  former  state  or  remedy  the 
evil ;  therefore,  when  forging,  watch  the  blast  and  see  that  the  thin 
edges  or  exposed  parts  do  not  heat  too  fast. 

In  tools  carrying  a  cutting  edge,  finishing  cold  and  hammer- 
ing hard  is  beneficial,  such  as  forgings  for  cutting  dies,  for  in- 
stance. 

Heating  for  Hardening. 

Then  comes  the  vital  process  of  hardening,  and  no  fixed  gen- 
eral rules  will  answer,  as  skill  and  experience  are  the  only  reliable 
standbys.  -However,  a  few  points  will  help  in  the  attainment  of 
satisfactory  results.  Heat  slowly  and  evenly  in  a  charcoal  or  a 
coal  fire  or  in  a  gas  muffle.  Most  mistakes  and  accidents  are  due 
to  the  steel  not  being  'heated  to  the  same  temperature  throughout ; 
particularly  is  this  so  in  large  articles  such  as  dies. 

If  possible,  dip  on  a  rising  heat,  that  is,  do  not  take  a  tool  from 
the  fire  and  wait  until  it  becomes  air  cool ;  see  that  you  get  it  the 


STEEL,    ITS   SELECTION   AND    IDENTIFICATION 


2O  HARDENING,    TEMPERING    AND   ANNEALING. 

required  heat  and  dip  at  once,  always  remembering  that  the  lowest 
heat  at  which  steel  will  harden  satisfactorily  gives  the  best 
results  in  hardness  and  toughness,  conditions  which  must  go  to- 
gether to  insure  satisfaction ;  therefore  do  not  exceed  a  low  red  in 
heating. 

Plain  water,  if  clear  and  cold,  will  generally  allow  of  harden- 
ing sufficiently ;  if  not,  brine  should  be  used.  There  are  also  a 
number  of  chemical  compounds,  receipts  for  which  are  given  in 
another  chapter  of  this  book,  which  give  excellent  results ;  a  prac- 
tical experiment  is,  however,  the  safest  to  go  by  in  adopting  them 
for  hardening  tools  for  different  uses. 

To  harden  small,  intricate  and  thin  tools,  which  must  not 
twist  or  warp  excessively  during  the  process,  an  oil  bath  will  be 
found  the  best  to  quench  in. 

Do  not  expose  heated  steel  to  a  current  of  air,  especially  in 
winter,  and  in  intricate  dies  or  milling  cutters  it  is  safer  to  allow 
them  to  cool  thoroughly  before  removing  them  from  the  quench- 
ing solution.  In  quenching,  a  strong  jet  of  water  will  help  to 
attain  good  results  when  hardening  large  dies,  etc. 

If  you  think  that  a  little  soap  or  oil  has  got  into  your  water 
bath,  a  handful  of  lime  will  clean  it.  The  best  way  to  do  in  a  case 
of  this  kind  is  to  simply  empty  the  tank  and  refill  it  with  perfectly 
clear  water. 

In  hardening  milling  cutters  or  similar  tools,  in  which  there 
is  likely  to  be  a  great  strain  placed  upon  the  tooth  at  its  exposed 
edges,  it  is  best  to  take  the  chill  out  of  the  water  by  plunging  a 
red  hot  piece  of  cast  iron  into  it.  In  some  cases  it  is  necessary 
to  protect  exposed  portions  of  such  tools  with  clay  and  thus  lessen 
unequal  contraction  and  strain. 

Never  attempt  to  harden  tool  steel  without  having  first  re- 
moved the  outer  scale  or  skin ;  this  applies  especially  to  annealed 
steel.  Also  always  remember  that  overheated  steel  will  usually 
crack  when  plunged  into  cold  water.  At  all  events  it  will  be 
useless  unless  restored. 

Treatment  of  Jessop's  Ijligh-Speed,   Self -Hardening   Steel. 

Heat  the  steel  uniformly  and  with  moderate  care,  forge  to 
shape  at  bright  red  and  do  not  hammer  cold.  Having  forged  to 
shape,  the  best  results  in  hardening  may  be  obtained  by  allowing 
the  tool  to  cool  before  the  process. 

To  harden :   Heat  the  nose  of  the  tool  to  almost  a  white  heat ; 


STEEL,     ITS    SELECTION    AND    IDENTIFICATION.  21 

do  not  be  afraid  of  burning  it,  but  when  white  hot  remove  and 
allow  to  cool  away  from  the  hearth.  From  the  high  temperature 
a  thick  scale  will  result,  which  should  be  thoroughly  removed  by 
grinding  on  a  wet  stone.  A  dry  emery  stone  is  usually  more  or 
less  detrimental  to  any  steel. 

After  using  a  tool  made  from  this  steel  for  some  time,  and 
regrinding  five  or  six  times  to  keep  up  its  cutting  qualities  to  the 
fullest  extent,  it  is  found  advisable  to  re-harden  as  described 
above,  doing  this  without  re-dressing  the  tool  unless  the  shape 
requires  alteration. 

Annealed  Tool  and  Die  Steel. 

Every  mechanic  appreciates  the  advantages  to  be  gained  in 
using  annealed  tool  and  die  steel,  as  it  obviates  the  necessity  of 
annealing  before  roughing,  economizes  time  and  overcomes  all 
risks  of  overheating  or  burning  during  the  process  of  annealing. 
After  roughing  it  may  be  heated  to  a  low  heat  and  left  to  cool 
and  then  finished,  when  the  results  in  hardening  and  tempering 
will  give  perfect  satisfaction. 

Treatment  of  Annealed  Tool  and  Die  Steel. 

In  hardening  tools  made  from  ready  annealed  steel,  heat  slowly 
and  uniformly  to  a  low  red  and  use  as  little  blast  as  possible. 
This  is  especially  needful  in  large  die  steel. 

In  forging,  above  all  things  avoid  overheating  and  a  strong 
blast.  Apply  the  heat  uniformly,  turning  over  the  article  in  the 
fire  so  as  to  give  the  heat  a  chance  to  reach  the  center.  Have  the 
fire  of  sufficient  size  to  allow  of  heating  the  article  all  over  and  see 
that  it  is  free  from  sulphur  or  other  impurities.  Never  try  to  heat 
a  large  block  of  steel  in  a  small  fire. 

Treatment  of  "Capital"  High-Grade  Steel. 
In  working  "Capital"  steel  it  must  be  heated  slowly  and  forged 
to  shape  at  a  heat  suitable  for  ordinary  cast  steel.  It  must  be 
heated  gradually  to  a  white  welding  heat  and  cannot  be  spoiled 
by  overheating  if  it  is  removed  from  the  fire, on  the  first  indica- 
tion of  its  reaching  a  melting  point.  It  must,  be  placed  instantly 
into  a  cold-air  blast  produced  by  .a  blower  or  compressed  air.  If 
the  nose  is  to  be  used  the  tool  should  be  held  on  a  direct  line  with 
the  blast,  but  not  too  close ;  as  soon  as  the  steel  stops  sparking 
turn  on  the  full  blast  of  air-pressure  and  hold  the  steel  within 
about  two  inches  of  the  nozzle  until  quite  cold. 


22 


HARDENING,    TEMPERING    AND    ANNEALING. 


After  the  air-hardening  process  the  tool  must  be  thoroughly 
ground,  as  the  high  heat  forms  a  thick  scale  which  must  be  re- 
moved entirely  in  order  for  the  tool  to  stand. 

In  hardening  it  is  also  advisable  to  have  the  cold  air  blast  as 


FIG.  4. — SET   OP   HARDENED  AND  TEMPERED  TURNING  TOOLS 
FOR   PRECISION   LATHE. 


STEEL,    ITS   SELECTION   AND   IDENTIFICATION  23 

near  as  possible  to  the  heating  arrangement,  so  that  the  tool  can 
be  transferred  immediately  from"  the  fire  to  the  blast.  On  no 
account  let  the  point  of  the  tool  shift  from  the  direct  air  current 
until  the  tool  is  cold.  If  the  article  is  laid  down  while  hardening 
it  must  be  fastened  securely  so  that  the  air  blast  will  not  shift  it. 

The  Best  Steel  for  Tools. 

The  question  that  has  been  asked  more  often  than  any  other 
of  steel  experts,  by  men  responsible  for  results  in  metal  working, 
is  :  "What  make  of  steel  is  the  best  for  general  tool  work?"  This 
question  has  never  been  answered  satisfactorily  and  it  never  will, 
as  no  two  men  handle  and  work  a  piece  of  steel  alike,  and  until 
mechanics  follow  instructions  given  for  the  working  of  the  dif- 
ferent brands  they  must  find  out  through  experience  the  best  make 
of  steel  for  their  special  purposes.  Any  of  the  leading  brands  of 
high-grade  steel  will  prove  satisfactory  for  general  tool  work  if 
heated  perfectly,  and  in  these  two  last  words  lies  the  attainment 
of  good  results. 

In  order  for  the  mechanic  to  work  steel  properly  he  must 
know  the  different  brands  and  adopt  them  for  purposes  which  ex- 
perience has  taught  him  they  are  the  best  suited.  Get  the  gen- 
eral knowledge  of  the  nature  and  peculiarities  of  the  different 
brands  of  steel  and  decide  for  yourself  the  purposes  for  which 
they  are  best  suited.  When  you  obtain  a  brand  that  works  well 
when  used  generally  stick  to  it. 

Testing  Tool  Steel. 

When  a  number  of  tools  are  to  be  made  from  the  same  bar  of 
steel,  unless  a  piece  of  this  particular  bar  has  been  used  before 
and  given  satisfaction,  it  is  well  to  test  it,  especially  when  ex- 
pensive tools  are  to  be  made  from  it.  A  good  way  to  do  this  is 
to  cut  off  a  thin  disk  from  one  end  and  harden  it  at  a  low  red 
heat.  After  the  piece  has  cooled,  dry  it  and  crack  it  through  the 
center.  Thus  any  defect  which  may  run  through  the  center  of 
the  bar  will  become  apparent.  If  there  are  any  defects,  return 
the  bar  to  the  manufacturer. 

The  Grain  of  Steel. 

If  the  steel  proves  sound  the  grain  should  be  examined.  In 
doing  this  do  not  wet  the  fracture,  as  this  would  discolor  the  steel 
and  prevent  examination.  If  the  steel  is  good  the  grain  will  ap- 
pear fine  and  close ;  if  bad,  a  coarse  appearance  will  be  presented, 


24  HARDENING,    TEMPERING    AND    ANNEALING. 

similar  to  broken  cast  iron.  A  coarse  grain  steel  should  never 
be  used  for  tools  which  will  be  subjected  to  much  strain,  such  as 
milling  cutters,  for  instance.  For  hardness,  test  the  center  of  the 
fracture  with  a  sharp,  smooth  file.  If  great  hardness  is  required, 
break  a  piece  so  as  to  leave  a  sharp  point ;  if  the  point  cuts  glass, 
the  steel  will  harden  satisfactorily  throughout. 

Testing  Steel  for  Toughness. 

A  great  many  steels  will  show  a  fine  grain  and  will  be  of 
sufficiently  high  carbon  percentage  to  allow  of  hardening  satis- 
factorily, but  will  not  prove  tough  enough  for  general  usage.  In 
making  expensive  tools  this  quality  should  be  determined  before 
proceeding  with  the  machining.  Harden  a  disk  and  place  it  upon 
an  anvil  and  strike  the  center  a  heavy  blow  with  a  hammer.  If 
it  breaks  instantly  it  is  too  brittle  and  is  not  tough  enough,  but  if, 
on  the  contrary,  several  blows  are  required  to  break  it  and  at  the 
last  blow  the  disk  flattens  a  bit,  it  is  fine  steel  and  may  be  used 
without  fear  of  subsequent  failure  in  hardening. 

Economy  in  Testing  Steel  Before  Using. 
While  these  testing  methods  are  rather  costly  in  the  beginning, 
and  in  a  great  many  cases  can  be  dispensed  with,  their  adoption 
when  making  a  number  of  costly  tools  will  often  prevent  expensive 
mistakes.  Where  a  large  amount  of  tool  steel  is  used,  some  one 
should  be  assigned  to  the  task,  and  when  a  lot  of  steel  comes  in 
he  should  cut  a  disk  off  each  bar  in  the  power  hack  saw,  mark 
each  disk  and  its  bar,  and  after  a  sufficient  number  of  disks  are 
at  hand  he  should  test  them.  Thus  at  a  moderate  cost  the  cer- 
tainty of  the  steel  being  satisfactory  for  required  uses  will  be 
determined,  a  large  number  of  costly  accidents  possibly  averted, 
and  a  vast  amount  of  time  saved  through  the  obviation  of  indi- 
vidual testing  by  the  tool-makers. 

Decarbonized  Steel  Surfaces. 

A  fact  which  few  tool-makers  seem  to  realize,  and  one  which 
if  generally  known  would  save  much  trouble,  is  that  the  surfaces 
of  all  steels  as  they  come  from  the  manufacturer  are  decarbonized 
and,  of  course,  will  not  harden.  This  condition  cannot  be  over- 
come in  the  present  manufacture  of  steel,  as  the  action  of  the 
oxygen  in  the  air  affects  the  steel  in  such  a  manner,  as  it  is  put 
through  the  various  operations  required  in  its  production,  as  to 
burn  out  the  carbon  in  the  surfaces.  For  this  reason  do  not 


STEEL,    ITS   SELECTION    AND    IDENTIFICATION  2$ 

select  a  piece  of  steel  which  will  just  "skin"  up,  but  take  a  piece 
large  enough  to  require  taking  a  good-sized  cut  off  before  reach- 
ing the  finishing  surface. 

How  to  Know  Tool  Steel  from  Mild  Steel 

In  a  great  many  shops  very  little  attention  is  given  to  the 
steel  corner,  rack,  or  box ;  the  floor  is  the  most  popular  place  for 
steel  storage  in  a  number  of  shops.  Very  often  machinery  steels 
and  tool  steels  are  piled  together  in  one  heap,  and  when  the  ma- 
chinist goes  to  secure  a  piece  he  has  to  wonder  "which  is  which." 
There  are  any  number  of  means  for  finding  this  out,  but  we  give 
here  a  very  quick  way.  To  test  a  piece  of  steel,  touch  the  end 
lightly  against  a  dry  emery  wheel  and  watch  the  sparks  as  they 
strike.  A  tool  steel  gives  forth  a  spark  which  seems  to  burst 
into  a  bright  point  of  light  when  it  strikes  against  the  frame  of 
the  grinder,  while  a  spark  from  machinery  steel  is  merely  a  dull 
red  incandescent  particle.  All  air-hardening  steels  give  forth 
bright  red  sparks. 

Tool  Hold'er  and  Tools. 

The  engraving,  Fig.  5,  shows  a  simple  home  made  tool  holder 
for  lathe  or  planer,  while  Fig.  6  shows  a  set  of  tools  to  be  used 


FIG     5. — A   LATHE   TOOL   HOLDER. 


HARDENING,    TEMPERING    AND    ANNEALING. 


Thread 


Broad 

Nose 


Corners 


Rough  oul 
Slots 


\    Rounding 
\      Corners 


Flat  Bottom 
Threads 


Z7 


7—^ — v — ^ 


Cast  Iron  // 


V 


L 


Side  Tools 


<3 


Brass  Parting 

Turning  Tools 


<\ 


Tool  for  Shaper 


FIG.  6.— SET   OF  SELF-HARDENING  STEEL-CUTTING  TOOLS. 


STEEL,    ITS   SELECTION    AND   IDENTIFICATION  27 

with  it.  Neither  will  require  a  description.  A  set  of  these  tools 
and  a  holder  of  the  construction  shown  will  be  found  handy 
things  for  a  tool-maker  to  have  in  his  drawer. 

Self -Hardening  Steel  Cutting  Tools. 

A  great  many  machinists  complain  about  self-hardening  steel 
cutting  tools,  and  say  that  it  is  impossible  to  accomplish  fine  re- 
sults in  turning  or  planed  work  with  them,  and  for  that  reason 
a  great  many  will  not  use  them.  Now,  when  they  say  that  for 
fine  work  they  are  useless,  they  are  right,  as  it  is  impossible  to 
get  the  edges  of  such  tools  to  keep  a  keen  edge  for  any  length 
of  time  so  as  to  allow  of  taking  smooth  finishing  cuts.  But  for 
medium  cuts  and  feeds  and  coarse  thread  cutting,  machining 
cast  iron  in  the  shaper,  planer  or  lathe,  for  turning  brass  castings 
and  also  for  accomplishing  different  operations  on  cast  iron  parts 
in  the  turret  lathe,  they  are  unequaled  and  should  always  be  used 
where  the  production  of  machine  parts  at  the  minimum  of  cost 
and  labor  is  imperative.  For  the  face-milling  of  large  castings, 
where  inserted  tooth  cutters  are  adaptable,  the  self-hardening 
steel  tools  will  be  found  to  give  the  best  results.  There  are  sev- 
eral brands  of  self-hardening  steel  on  the  market  in  any  one  of 
which  it  will  be  found  possible  to  hold  an  edge  sufficiently  keen  to 
allow  of  its  being  used  for  the  purposes  herein  enumerated. 

Speeds  of  Cutting  Tools. 

To  secure  the  best  results  from  steel  used  for  cutting  purposes 
attention  must  be  given  to  the  use  of  calculations  in  or  for  de- 
termining the  proper  speed  for  the  work  or  tool,  according  to 
conditions.  As  a  rule  the  average  machinist  does  not  in  ordinary 
practice  make  use  of  these  rules,  but  instead  depends  on  the 
knowledge  acquired  through  experience  and  observation.  For 
the  benefit  of  those  who  are  not  familiar  with  rules  for  finding 
cutting  speeds,  and  to  obviate  the  necessity  of  guessing  at  the 
proper  speed,  we  give  approximate  cutting  speed  at  which  tools 
or  work  should  be  run  in  the  machining  of  different  metals. 
Figs.  7  to  24  illustrate  tool  holders  and  tools  and  the  manner  in 
which  they  should  be  used. 

Cutting  speed  for  cast  iron,  14  to  16  circumference  or  longi- 
tudinal feet  per  minute. 

Cutting  speed  for  malleable  iron,  16  to  20  circumference  or 
longitudinal  feet  per  minute. 


28  HARDENING,    TEMPERING    AND    ANNEALING, 


FIG.  7  — RIGHT  AND  LEFT  SIDE 
TOOLS,    TURNING. 


FIG.  8. — RIGHT   AND    LEFT  SIDE 
TOOLS,    PLANING. 


FIG.  9. — PLANER  TOOL. 


FIG.   IO. — MANNER    IN   WHICH  PLANER 
TOOL   IS   USED. 


FIG.   12. — CUTTING-OFF  TOOL. 


FIG.  13. — OFFSET   CUTTING-OFF  TOOL. 


FIG.  14.  —  TURNING  TOOL  FOR  LATHE. 


FIG.  1  6;  —  BORING  TOOL, 


FIG.  15. — SHAPER  TOOL. 


FIG.  I/. — BORING  TOOL. 


STEEL,    ITS    SELECTION    AND    IDENTIFICATION. 


29 


PIG.   19. — BORING  TOOL. 


FIG.  22. —  "HOGGING  "  TOOL 


FIG.   20.  —  CUTTING   INSIDE 
THREAD. 


FIG.    23. — PARTS  OF    "HOGGING" 
TOOL. 


ARMSTRONG  THREADING  TOOL 
DROP  FORCED  Of  STEEL 


FIG.  21. — THREAD  TOOL. 


FIG.  24. — "HOGGING  "  CUT. 


3O  HARDENING,    TEMPERING    AND    ANNEALING. 

Cutting  speed  for  steel,  12  to  15  circumference  or  longitudinal 
feet  per  minute. 

Cutting  speed  for  brass,  28  to  40  circumference  or  longitudinal 
feet  per  minute. 

The  circumstances  and  conditions  upon  which  slight  variations 
of  the  speeds*  given  above  depend  are  numerous,  among  which 
are :  Whether  a  roughing  or  finishing,  coarse  or  fine  cut  is  being 
taken ;  the  form  and  shape  of  the  cutting  tools ;  the  toughness  and 
density  of  the  metals  worked  upon,  and  the  surface  feet  machined 
without  regrinding  the  tool.  There  is  a  great  deal  of  work  done 
in  the  lathe  or  in  the  planer  which  requires  tools  which  project 
far  out  of  their  holders.  For  such  work  the  cutting  speeds  must 
be  considerably  less  than  here  given.  Then,  very  often,  the  tex- 
ture of  the  metal  is  tough  and  hard,  necessitating  slower  speeds 
and  fine  feeds  in  machining.  For  these  reasons,  it  is  a  difficult 
matter  to  lay  down  any  exact  rules  for  the  accurate  calculating  of 
cutting  speeds ;  so  we  give  approximate  speeds  and  leave  their 
variation  to  the  machinist  to  determine  according  to  the  various 
conditions. 

Cutting  and  Durability  Qualities  of  Steel. 

The  capacity  of  steel  to  cut  lies  principally  in  its  temper, 
while  the  durability  of  the  cutting  edges  depends  upon  its  quality 
and  adaptability  to  the  kind  of  work  for  the  machining  or  cutting 
of  which  it  is  used.  Thus  to  secure  the  best  results  in  cutting 
tools,  steel  of  the  best  quality  must  be  used.  The  cost  of  good 
steel  for  tools  should  not  be  considered  of  much  importance  as 
compared  with  its  efficiency,  because  the  cost  is  insignificant  when 
compared  with  the  results  possible  to  attain  by  its  use.  Take, 
for  instance,  a  large  milling  cutter,  or  gang  of  small  milling  cut- 
ters, made  from  good  steel  and  weighing  a  few  pounds,  will  ma- 
chine many  tons  of  metal  without  requiring  grinding  if  subjected 
to  the  proper  hardening  and  tempering  processes.  The  time  re- 
quired to  machine  a  given  surface  depends  very  much  upon  the 
quality  of  the  steel  of  which  this  tool  or  tools  is  or  are  made,  and 
will  vary  thirty  or  forty  per  cent  from  a  very  slight  difference  in 
quality. 

With  a  steel  of  a  given  quality  the  efficiency  of  the  tools  made 
from  it  depends  most  upon  the  knowledge  and  skill  employed  in 
the  forging,  annealing,  hardening  and  tempering,  and  also  upon 
the  shape  of  the  cutting  edges.  So  in  considering  the  different 


STEEL,    ITS    SELECTION    AND    IDENTIFICATION.  31 

qualities  of  work  performed  by  tools  made  from  the  same  grade 
or  brand  of  steel,  we  must  first  know  of  the  amount  of  skill  em- 
ployed in  the  performance  of  the  heating  operations. 

Judgment,  Experience  and  Perception  in  the  Working  of  Steel. 

To  a  great  many  mechanics  any  steel  which  will  harden  is  con- 
sidered good  steel.  To  harden,  however,  is  a  very  simple  matter, 
but  to  harden  when  heated  to  a  definite  degree  requires  skill, 
and  to  harden  a  piece  of  steel  so  that  it  will  possess  a  definite  de- 
gree of  elasticity  when  tempered  to  a  particular  point  of  tempera- 
ture after  hardening  requires  skill  and  knowledge  both.  Thus 
if  all  steel  which  will  harden  is  good  steel,  and  as  there  is  an 
absence  of  uniformity  in  the  grades  of  steel  in  general  use,  the 
operator 'must  rely  on  judgment,  experience  and  perception  to 
attain  satisfactory  results. 

Even  when  the  steel  operated  upon  is  of  a  uniform  grade,  the 
heating  processes  will  not  always  bring  forth  uniform  results, 
because  steel  decarbonizes  somewhat  by  being  heated,  and  thus 
a  small  piece  or  tool  deteriorates  by  being  heated  in  the  open 
fire,  and  one  often  heated  to  repair  or  sharpen  suffers  in  propor- 
tion. From  all  this  it  will  be  understood  that  hardening  and 
tempering  processes  of  steel  must  differ  according  to  the  size 
and  nature  of  the  work,  the  amount  of  uniformity  required,  and 
the  results  which  the  tools  are  required  to  accomplish.  From 
all  these  considerations  we  are  forced  to  conclude  that  the  in- 
formation of  value  to  practical  men  and  the  only  way  to  instruct 
them  in  the  art  of  steel  treatment  is  by  presenting  the  practice  of 
the  best  shops  and  tool-makers  and  giving  the  processes  and  con- 
ditions in  connection  with  each  other.  • 

The  First  Effects  of  Heat. 

Norton,  in  his  "Elements  of  Natural  Philosophy,"  says: 
"The  first  effect  of  heat  on  any  body,  solid,  liquid  or  aeriform, 
is  to  expand  it. 

"The  expansion  of  gases  may  be  readily  shown  by  an  air 
thermometer.  This  consists  simply  of  a  bulb  of  glass,  with  a 
long  narrow  stem,  dipping  into  colored  water.  If  the  bulb  be 
warmed  by  the  hand,  the  air  within  will  so  expand  that  a  portion 
will  be  expelled  and  rise  in  bubbles  through  the  liquid.  On  cool- 
ing, the  portion  of  air  remaining  will  contract  to  its  former 
volume,  and  the  water  will  take  the  place  of  the  air  expelled. 


32  HARDENING,    TEMPERING   AND   ANNEALING. 

"The  experiment  may  then  be  continued  indefinitely.  The 
expansion  and  contraction  may  be  measured  by  the  scale  attached 
to  the  stem ;  it  will  be  found  that  all  expand  equally  and  regularly 
for  successive  increments  of  heat. 

Unequal  Expansion. 

"The  unequal  expansion  of  different  metals  is  well  shown  by 
a  compound  bar,  made  by  riveting  together  two  bars  of  iron  and 
brass,  at  different  points  along  their  whole  length.  .  .  . 

"If  the  bar  is  straight  at  ordinary  temperature,  it  will  so  bend 
when  hot  water  is  poured  on  it  that  the  brass  will  be  on  the  con- 
vex side  of  the  curve,  and  bend  in  the  opposite  direction  when 
cold  water  is  poured  on  it.  The  brass  expands  and  contracts 
more  than  the  iron,  and  the  bar  curves  to  accommodate  the  in- 
equality of  the  length  which  results.  This  principle  has  been 
applied  to  the  construction  of  metallic  thermometers. 

Heat  Effects  on  Clay. 

"Clay  does  not  expand  by  heat,  but  contracts  permanently,  by 
reason  of  chemical  changes  in  its  particles.  In  the  experiments 
detailed,  the  bodies  will  be  found  to  contract  on  cooling  and  as- 
sume their  original  volume  as  soon  as  they  attain  their  former 
temperature.  Certain  metals,  as  lead  and  zinc,  are  exceptions 
to  this  law  of  cooling,  the  contraction  being  at  each  time  a  little 
less  than  the  expansion. 

"From  this  experiment  it  is  evident  (i)  that  the  volume  of  all 
bodies  is  increased  by  heat;  (2)  that  this  increased  volume  is  due 
to  motion  among  the  molecules  of  the  bodies,  which  tends  con- 
tinually to  separate  them;  (3)  that  the  intensity  of  the  heat  may 
be  measured  by  the  degree  of  the  molecular  motion.  From  these 
and  other  considerations  it  is  assumed  that  heat  is  that  mode  of 
molecular  motion  which  may  be  measured  by  the  expansion  of 
bodies. 

"By  this  definition  it  is  understood,  ( i )  that  the  molecules  of 
every  body  are  in  continual  motion;  (2)  that  when  this  motion 
increases  in  intensity  the  body  becomes  warmer;  (3)  that  when 
this  motion  decreases  in  intensity  the  body  becomes  cooler.  An 
older  theory,  which  regarded  heat  as  imponderable  matter,  has 
been  generally  discarded,  while  some  of  its  terms  have  been  re- 
tained ;  hence  it  must  be  understood  that  when  heat  is  described  as 
passing  from  one  body  to  another,  it  means  that  the  molecular 


STEEL,    ITS    SELECTION    AND    IDENTIFICATION.  33 

motion  of  one  body  is  communicated  to  the  molecules  of  another, 
and  not  that  any  material  agent  has  passed  between  them. 

The  Amount  of  Force  Exerted  in  Expansion  or  Contraction. 

"The  amount  of  force  exerted  in  expansion  and  contraction 
is  enormous,  for  it  is  equal  to  that  which  would  be  required  to 
stretch  or  compress  the  material  to  the  same  extent  by  me- 
chanical means. 

''Water,  at  the  temperature  128  deg.  Fahrenheit  is  compressed 
.000044  of  its  volume  by  the  pressure  of  one  atmosphere.  On 
being  heated  from  32  deg.  Fahrenheit  to  212  deg.  Fahrenheit  it 
expands  .0466  of  its  volume.  Therefore,  to  restore  boiling  water 
to  its  bulk  at  freezing  would  require  a  pressure  of  over  one  thou- 
sand atmospheres.  The  expansive  force  of  water  for  each  de- 
gree Fahrenheit  is  nearly  ninety  pounds  per  square  inch.  Hence, 
if  a  closed  vessel  be  completely  filled  with  cold  water,  it  must 
speedily  burst  when  heat  is  applied. 

"A  bar  of  wrought  iron  expands,  for  each  degree  Fahrenheit, 
with  a  force  of  nearly  two  hundred  pounds  to  the  square  inch. 
This  force  had  a  curious  application  in  the  Museum  of  Arts  and 
Trades  in  Paris.  The  walls  of  an  arched  gallery  had  bulged 
outward  by  the  weight  of  the  arch.  Iron  bars  were  placed  across 
the  building  and  screwed  into  plates  on  the  outside.  The  alternate 
bars  were  then  heated,  and  as  soon  as  they  had  expanded  the  plates 
were  screwed  up  tightly  to  the  walls.  As  the  bars  cooled  and 
contracted,  they  drew  the  walls  closer  together.  The  operation 
was  repeated  until  the  walls  had  attained  the  vertical  position. 

"On  the  same  principle  tires  are  fastened  on  wheels.  The 
tire,  made  a  little  smaller  than  the  wheel,  is  heated  red  hot,  and 
while  expanded  is  placed  in  position.  On  cooling,  it  not  only 
secures  itself  on  the  rim,  but  holds  all  the  other  parts  of  the  wheel 
in  position. 

"It  is  cften  necessary  to  take  into  account  the  changes  of 
length  produced  by  heat.  In  railways  a  small  interval  must  be 
left  between  the  ends  of  the  iron  rails.  Iron  bars  built  into 
necessary  lengths  should  be  left  free  at  one  end. 

"Brittle  substances,  as  glass  and  cast  iron,  often  crack  on  being 
heated  suddenly,  because  the  outside  is  heated  sooner  than  the 
inside,  and  thereby  causes  an  unequal  expansion.  A  sudden 
cooling,  by  inducing  unequal  contraction,  has  the  same  effect. 
The  thicker  the  plate  the  greater  the  liability  to  fracture. 


34  HARDENING,    TEMPERING    AND    ANNEALING. 

The  Second  Effect  of  Heat. 

"The  second  effect  of  heat  on  a  solid  is  to  change  its  molecular 
condition  to  melt  it.  Some  solids,  as  paper,  wood  and  wool,  do 
not  melt,  but  are  decomposed.  The  temperature  at  which  solids 
melt  differs  for  different  substances,  but  is  invariable  for  the  same 
substance,  if  the  pressure  is  constant.  This  temperature  is  called 
the  melting  point. 

Table  of  Expansion  from  32  dcg.  F.  to  212  dcg.  F. 

Linear.  Cubical. 

Solids.                                                                i  i 

Flint  glass   1/1248  1/416 

Platinum    1/1131  I/377 

Steel    1/926  1/309 

Iron    1/846  1/282 

Brass 1/536  1/179 

Silver    1/524  I/I75 

Zinc 1/340  1/113 

Tin    1/516  1/172 

Fluids. 

Mercury    1/55 

Water 1/21.3 

The  fixed  oils   1/12 . 5 

Alcohol 1/9 

Air  and  permanent  gases 180/491" 

KMs  of  Steel  Produced  in  America  by  the  Crucible  and  Open 
PI  earth  Processes. 

Steel  is  produced  in  America  by  the  crucible  and  open-hearth 
processes  in  bars,  rods,  sheets,  plates,  wire,  forgings  and  rolled 
shapes. 

The  different  kinds  of  steel  produced  by  these  methods  com- 
prise :  Fine  tool  and  die  steel,  self-hardening  steel,  ax  and  hatchet 
steel,  cutlery  steel,  surgical  and  fine  knife  steel,  composite  die  steel, 
oil  well  and  artesian  bit  steel,  mining  drill  steel,  annealed  die- 
blocks  and  cutter  blanks,  tool  steel  forgings,  circular  and  long 
saw  plates,  boiler  and  fire  box  plates,  hot-rolled  and  cold-rolled 
strip  steel,  polished  high-grade  drill  rods  and  wire,  needle  wire> 
resistance  wire  rods,  music  wire  rods,  nickel  steel  rods;  wire  of 
every  grade,  shape  and  size,  bright,  annealed  and  tempered  ;  cru- 


STEEL,    ITS    SELECTION    AND    IDENTIFICATION.  35 

cible  steel  rods,  clock  and  watch  spring  steel,  pen  steel,  magnet 
steel,  heavy  gun  forgings  and  projectiles,  gun  barrel  steel,  spring 
steel,  machinery  steel,  merchant  bar  steel,  machinery  steel  forg- 
ings, cold-drawn  screw  steel,  hammer  and  sledge  steel,  welding 
steel,  soft  center  and  soft  back  plow  steel,  agricultural  steel  of  all 
descriptions,  sleigh  shoe  and  toe-calk  steel,  wedge  steel,  laminated 
safe  steel,  skate  steel,  etc. 

One  of  the  largest  producers  of  steel  in  the  world,  by  the  cru- 
cible and  open-hearth  processes,  is  the  Crucible  Steel  Company 
of  America,  Pittsburg,  Penn.  This  company's  products  include 
all  of  the  steels  above  enumerated  as  well  as  many  others  too 
numerous  to  mention. 


CHAPTER  II. 

ANNEALING  PROCESSES THE  TERMS  ANNEALING,   HARDENING  AND 

TEMPERING  DEFINED THE   ANNEALING   OF   MALLEABLE    CAST- 
INGS. 

The  Terms  Defined. 

Annealing,  hardening  and  tempering,  are  three  terms  used  to 
distinguish  the  different  processes  through  which  tool  steel  and 
various  other  metals  are  required  to  pass  in  order  to  allow  of  their 
being  used  for  the  various  purposes  required  in  the  arts.  In 
order  that  the  mechanic  may  be  able  to  adopt  these  processes  to 
the  best  advantage  in  the  making  of  tools  for  different  kinds  of 
work,  he  must-  learn  that  annealing  means  something  more  than 
heating  a  piece  of  steel  red  hot  and  allowing  it  to  cool ;  hardening 
more  than  heating  red  hot  and  plunging  into  water,  and,  that 
tempering,  something  more  than  coloring  a  piece  of  steel.  In  fact 
he  must  realize  that  the  annealing,  hardening  and  tempering  of 
steel  is  an  art  in  itself,  and  that  in  order  to  become  skilled  in  it, 
constant  vigilance,  experience  and  study  are  necessary,  from  "the 
ground  up." 

Metals  are  annealed  by  slowly  cooling  them  from  a  high  tem- 
perature. Annealing  generally  increases  the  flexibility,  softness, 
and  ductility  of  bodies,  and  in  this  manner  metals  that  have  be- 
come brittle  through  excess  of  strain  in  rolling,  drawing,  twisting, 
hammering,  forging  or  other  mechanical  means,  may  have  their 
properties  restored  by  annealing. 

Steel  and  a  number  of  other  metals,  if  cooled  suddenly  after 
having  been  heated  to  a  high  temperature,  become  more  brittle  and 
more  elastic  than  before.  For  instance,  if  a  piece  of  tool  steel  is 
heated  to  a  white  heat  and  then  plunged  into  a  bath  of  ice-water 
or  mercury,  it  will  become  almost  as  hard  as  a  diamond,  and  will 
be  very  elastic  and  so  brittle  that  it  can  only  be  used  for  drilling 
tempered  steel  or  chilled  iron,  or  for  coining  and  engraving  dies 
and  files  of  the  hardest  kinds. 

When  steel  is  in  its  softened  condition  it  may  be  worked  into 
any  shape  required  in  the  arts.  To  harden  steel  after  it  Has  been 
worked,  it  is  strongly  heated  and  suddenly  cooled,  and  as  it  is 
rendered  too  brittle  by  this  hardening  process  (for  ordinary  pur- 


ANNEALING   PROCESSES.  37 

poses,  at  least),  something  of  its  elasticity  must  be  sacrificed  and  a 
portion  of  its  hardness  removed  by  reheating  the  steel  to  a  lower 
temperature  and  allowing  it  to  cool  slowly.  This  process  is  called 
"drawing"  or  "tempering."  The  temper  to  which  a  piece  of  steel 
should  be  drawn  depends  upon  the  use  to  which  it  is  to  be  put, 
and  is  regulated  by  varying  the  temperature  of  the  second  heat- 
ing, the  higher  the  degree  of  heat  the  softer  the  steel. 

When  a  steel  tool  or  article  has  been  hardened,  then  polished 
or  ground  and  reheated,  the  film  of  oxide  on  its  surface  becomes, 
at  a  temperature  of  420  deg.  F.,  of  a  light  straw  color,  then 
through  intermediate  hues  to  a  violet  yellow  at  509  deg.  F.,  blue 
at  550  deg.  F.,  while  at  725  deg.  F.  the  steel  passes  to  a  red  heat. 
These  colors  guide  the  workman  in  his  efforts  to  temper  the 
tools  as  required.  Light  yellow  is  the  temper  required  for  all 
articles  or  tools  requiring  a  keen  edge ;  a  deeper  yellow  for  fine 
cutlery,  while  violet  is  the  temper  for  table  knives  requiring  flexi- 
bility more  than  a  hard  brittle  edge,  and  blue  for  all  articles  or 
tools  which  are  required  to  be  very  flexible. 

How  to  Thoroughly  Anneal  High-Carbon  Tool  Steel  Parts. 

Very  often  a  large  number  of  accurate  small  tools  are  to-be 
made  from  high-carbon  steel,  and  as  they  are  required  to  be 
hardened  perfectly  so  as  to  not  warp,  bulge,  crack  or  shrink  ex- 
cessively, they  must  be  perfectly  annealed  before  finishing. 

The  most  satisfactory  method  for  annealing  high  grade  tool 
steel  parts  is  to  pack  in  granulated  charcoal  in  an  iron  box,  ar- 
ranging the  parts  so  that  they  will  not  come  higher  than  within 
one  inch  of  the  top  of  the  box,  and  cover  with  well  packed  char- 
coal. Then  place  the  box  in  the  furnace  or  forge  and  heat  to  a 
bright  red,  at  which  it  should  be  held  for  some  time,  depending 
upon  the  size  of  the  parts  to  be  annealed.  For  instance,  parts 
not  over  one  inch  in  diameter  or  thick,  if  kept  at  a  red  heat  for 
an  hour,  after  a  through  heat,  will  be  found  to  have  annealed  as 
desired ;  large  pieces  must  be  kept  hot  for  a  period  correspond- 
ing to  their  size  and  shape.  After  the  heat,  allow  the  box  to 
cool  off  slowly  and  do  not  remove  the  parts  until  perfectly 
cool. 

The  Proper  Heat  for  Annealing. 

It  has  been  found  through  experience  that  the  proper  Heat 
for  annealing  is  almost  a  forp-in^  he?>t.  Keep  at  a  bright  red 
long  enough  to  overcome  all  strains  which  may  have  a  tendency 

•ft 


38  HARDENING,    TEMPERING    AND    ANNEALING. 

to  manifest  themselves  during  the  hardening  process.  It  is  not 
well  to  use  cast  iron  chips  or  turnings  for  packing,  as  they  will 
decarbonize  the  steel  to  such  an  extent  as  to  prevent  successful 
hardening  afterward.  Packing  parts  too  near  to  the  walls  of 
the  annealing  box  will  have  almost  the  same  effect  as  the  chips ; 
in  fact,  it  will  be  worse,  as  the  decarbonizing  effect  will  be  unequal 
and  the  surfaces  nearest  the  box  sides  will  be  affected,  thus  mak- 
ing whatever  hardening  possible  unequal. 

Annealing  in  the  Charcoal  Fire. 

A  great  many  shops  have  not  the  facilities  to  allow  of  using 
the  above  described  annealing  process,  and  in  such  very  satisfac- 
tory results  may  be  attained  by  heating  the  steel  in  a  good  char- 
coal fire  to  about  an  even  forging  heat.  After  heating,  put  a 
few  inches  of  the  fire  ash  in  a  box,  and  on  top  of  the  ash  place 
a  soft  pine  board,  then  place  the  heated  work  on  top  and  cover 
the  box.  TRe  wood  will  char  and  smolder  and  the  steel  will  re- 
main hot  for  a  considerable  period.  Often  a  box  of  cold  ashes 
may  be  used  to  accomplish  the  same  results  to  a  less  extent,  as  the 
cold  ashes  or  lime — either  one  acts  the  same — are  apt  to  chill  the 
hot  steel.  However,  when  either  of  the  three  materials  are  used 
hot,  good  results  will  be  obtained. 

Good  Steel  for  Good  Tools. 

One  of  the  points  that  a  great  many  mechanics  seem  to  forget 
is  the  necessity  of  having  good  steel  in  order  to  do  good  tool- 
making.  Often  upon  asking  a  toolmaker,  who  was  engaged  in 
making  a  tool  or  die,  what  brand  of  steel  he  was  using,  the 
writer  has  been  met  with  the  answer:  "I  don't  know."  Make  it 
your  business  to  discover  the  best  brands  for  different  purposes 
and  then  stick  to  them.  A  steel  that  is  good  steel  will  show,  when 
hardened  and  broken,  a  white  fracture  free  from  coarse  spots. 
Get  a  steel  of  a  carbon  percentage  that  will  allow  of  its  being  an- 
nealed and  hardened  at  a  low  red  heat,  as  steel  which  requires 
a  very  high  heat  to  anneal  and  harden,  will,  nine  times  out  of  ten, 
prove  utterly  unsatisfactory,  and  tools  made  from  it  will  crack, 
chip  or  spring  when  in  use. 

Annealing. 

Although  it  does  not  seem  to  be  generally  known,  the  suc- 
cessful hardening  of  a  piece  of  steel  depends  greatly  on  the  an- 


ANNEALING    PROCESSES.  39 

nealing  of  it  previous  to  machining  it,  and  in  order  to  harden 
properly  it  is  necessary  that  the  correct  processes  of  annealing 
should  be  understood.  Always  anneal  any  odd-shaped  piece,  or 
one  with  an  irregular-shaped  hole  in  it,  after  having  roughed  it 
down.  The  best  way  to  anneal  such  pieces  is  to  pack  them  in 
charcoal  in  an  iron  box,  being  sure  to  have  as  much  charcoal  at  the 
sides  of  the  box  as  at  the  bottom,  in  order  that  the  heat  shall  not 
penetrate  too  quickly.  The  box  should  be  kept  at  a  red  heat  for 
an  hour,  and  then  left  in  the  ashes  over  night  to  cool.  The  proper 
heat  for  such  pieces  in  annealing  should  always  be  higher  than  the 
heat  required  to  harden  the  same  piece.  Experience  has  taught 
us  that  a  heat  almost  as  high  as  a  forging  heat  will  be  the  means 
of  overcoming  any  undue  tension  or  strain  which  may  become  ap- 
parent when  the  piece  is  hardened. 

An  Annealing  Bo.v  for  Small  Parts. 

A  good  way  to  make  an  annealing  box  for  small  parts  is  to  take 
a  piece  of,  say,  3-inch  iron  pipe  about  10  inches  long.  Tap  both 
ends  of  the  pipe  and  fit  plugs  to  them;  cast  iron  will  do.  One  of 
the  ends  may  then  be  closed  and  the  charcoal  and  parts  to  be  an- 
nealed packed  in,  after  which  the  other  plug  can  be  screwed  in. 
With  a  box  of  this  kind  no  sealing  is  necessary,  as  the  screw  plugs 
prevent  the  entrance  of  the  air. 

Water  Annealing. 

Very  often  a  piece  of  steel  is  required  for  a  repair  job  or  some 
other  job  in  a  hurry,  and  there  is  no  time  to  anneal  it  in  the  regu- 
lar way.  At  other  times  a  piece  which  has  been  hardened  re- 
quires to  be  machined.  When  confronted  with  the  above  condi- 
tions, a  tool-maker  can  fall  back  on  the  "water  annealing"  and 
after  he  has  tried  it  a  few  times  he  will  be  delighted  with  the  re- 
sults. There  are  several  methods  of  doing  this,  and  we  give  here 
the  best  of  them  all :  The  mechanic  may  adopt  any  of  them,  accord- 
ing to  the  results  secured  from  each.  The  first  method  is  to  heat 
the  steel  slowly  to  a  dull  cherry  red ;  then  remove  it  from  the  fire 
and  with  a  soft  piece  of  wood  try  the  heat,  as  it  decreases,  by 
touching  the  steel  with  the  end  of  the  stick.  When  the  piece  has 
cooled  so  that  the  wood  ceases  to  char,  plunge  the  steel  quickly 
into  an  oil  and  water  bath.  On  machining  the  steel  it  will  be 
found  to  be  very  soft. 

The  second  method  for  water  annealing  is  to  heat  the  steel 


4O  HARDENING,    TEMPERING    AND    ANNEALING. 

slowly  to  a  red  heat,  then  allow  it  to  lie  in  the  ashes  a  few  min- 
utes until  almost  black,  then  drop  it  into  soapsuds  and  allow  it 
to  cool. 

Very  often  a  piece  of  steel  annealed  in  this  manner  will  turn 
out  much  softer  than  if  annealed  in  the  regular  manner  by  packing 
in  powdered  charcoal  and  allowing  it  to  cool  over  night.  A  good 
way  to  make  sure  as  to  the  time  to  drop  the  steel  into  the  bath, 
is  to  allow  it  to  cool  until  almost  black,  then  touch  it  with  a  file, 
if  the  steel  does  not  brighten  for  an  instant  and  then  turn  blue, 
wait  a  few  seconds  and  repeat  the  experiment.  If,  upon  the 
second  trial,  the  blue  appears  and  then  a  spark  right  afterward, 
drop  the  steel  instantly  into  the  bath,  and  when  cool  it  will  be 
found  to  be  as  "soft  as  butter." 

Sometimes  a  piece  of  steel  which  is  to  be  used  as  a  punch  or 
die  blank,  upon  starting  to  machine  it,  proves  hard,  although  it 
has  been  annealed.  When  this  is  the  case,  never  try  to  finish  it 
before  reannealing  it ;  instead,  rough  it  down,  clean  out  the  cen- 
ters and  anneal  it  over  again.  The  time  required  to  rqanneal  a 
piece  of  steel  will  be  more  than  made  up  in  the  machining  of  it. 

The  Effects  of  the  Water  Anneal. 

Although  it  may  seem  strange  to  some,  it  is  a  fact  that  results 
possible  to  attain  in  steel  which  has  been  water  annealed  cannot 
be  obtained  by  any  other  methods.  Water  annealing  seems  to 
give  a  certain  texture  to  the  grain  of  the  steel,  which  is  not  ex- 
actly softness,  but  is  different  from  that  obtained  by  charcoal  ash 
annealing.  When  a  piece  of  steel  has  been  properly  water  annealed 
and  is  turned  in  the  lathe  using  a  lubricant,  it  will  present  a 
strange  dead-white  appearance  and  the  turnings  will  be  short 
and  come  off  like  little  bristles. 

In  steel  annealed  in  the  usual  manner  the  turnings  will  gen- 
erally come  off  in  long  close-curled  lengths,  and  the  surface 
of  the  work  will  present  a  more  or  less  torn  texture,  even  when 
the  tool  used  is  very  keen.  This  tearing  is  caused  by  the  steel 
being  so  soft  as  to  give  way  and  crowd  up  into  little  lumps  just 
slightly  ahead  of  the  cutting  edges  of  the  tool.  Thus  in  cutting 
screw  threads  in  ordinary  annealed  steel  it  is  almost  impossible  to 
get  a  smooth,  clean  thread. 

The  water  annealing,  however,  seems  to  overcome  this  un- 
pleasant feature,  in  that  it  seems  to  give  the  requisite  stiffness 
of  texture  to  prevent  this  tearing.  Considering  the  results,  the 


ANNEALING   PROCESSES.  4! 

water  anneal  will  contribute  to  the  best  results  being  attained  in 
a  large  variety  of  lathe  work. 

We  are  unable  to  state  just  what  chemical  or  molecular  action 
the  water  anneal  has  on  steel.  It  is  not  a  softening  action,  as 
compared  with  the  effects  of  ordinary  annealing,  but  instead  a 
stiffness  and  tightness  of  the  particles  which  allows  the  cutting 
edge  of  the  tool  to  creep  beneath  the  shell  and  peel  it  off. 

The  Annealing  of  Tap  Steel. 

Most  of  the  large  establishments  in  which  taps,  reamers,  etc., 
are  manufactured  have  most  of  their  steel  annealed  at  the  places 
where  it  is  made.  This  has  been  done  for  some  years  with  the 
possible  exception  of  the  steel  from  which  long  stay-bolt  taps 
are  made,  they  having  been  found  to  require  more  care  in  anneal- 
ing than  the  steel  manufacturers  give  them. 

During  an  interview  a  few  years  ago,  Mr.  F.  A.  Pratt,  of  the 
famous  American  firm  of  Pratt  &  Whitney,  spoke  as  follows  in 
regard  to  the  working  of  tap  steel : 

"We  have  most  of  our  tap  steel  annealed  at  the  place  where 
it  is  made.  We  have  had  it  done  in  this  way  for  some  years,  with 
the  exception  of  our  long  stay-bolt  taps,  which  we  have  found 
to  require  more  care  in  annealing  than  the  steelmakers  give  them. 

"More  steel  is  injured,  and  sometimes  spoiled,  by  over-anneal- 
ing than  in  any  other  way.  Steel  heated  too  hot  in  annealing  will 
shrink  badly  when  being  hardened ;  besides,  it  takes  the  life  out 
of  it.  It  should  never  be  heated  above  a  low  cherry  red,  and  it 
should  be  a  slower  heat  than  it  is  when  being  hardened.  It  should 
be  heated  slowly  and  given  a  uniform  heat  all  over  and  through 
the  piece. 

"This  is  difficult  to  do  in  long  bars  and  in  an  ordinary  furnace. 
The  best  way  to  heat  a  piece  of  steel,  either  for  annealing  or 
hardening,  is  in  red  hot,  pure  lead.  By  this  method  it  is  done 
uniformly  and  one  can  see  the  color  all  the  time.  We  do  some 
heating  for  annealing  in  this  way,  and  simply  cover  up  the  piece 
in  saw-dust,  and  let  it  cool  there,  and  we  get  good  results.  All 
steelmakers  know  the  injurious  effects  of  over-heating  steel  and  of 
over-annealing,  but  their  customers  are  continually  calling  for 
softer  steel  and  more  thorough  annealing.  Until  users  are  edu- 
cated up  to  the  idea  of  less  annealing  and  to  working  harder  steel, 
both  will  suffer,  for  the  user  will  continually  complain  of  poor 
steel. 


42  HARDENING,    TEMPERING    AND    ANNEALING. 

"Several  years  since  we  caught  on  to  the  fact  that  steel  was 
injured  by  over-annealing,  and  that  good  screw  threads  could  not 
be  cut  in  steel  that  was  too  soft ;  our  men  would  rather  take  the 
steel  bar  direct  from  the  rolls  without  any  annealing  than  take  the 
risk  of  annealing.  At  present  we  get  it  from  the  makers  in  passa- 
ble condition,  but  not  as  it  should  be,  and  unless  the  steelmakers 
find  some  way  to  heat  the  bars  to  a  uniform  heat,  and  at  a  low 
cherry  red,  we  must  either  use  it  raw  from  the  bar  or  anneal 
it  ourselves.  We  find,  also,  that  this  soft  annealing  makes  a  much 
greater  shrinkage  and  spoils  the  lead  of  the  thread,  and  that  from 
the  bar  without  any  annealing  there  is  very  little  trouble  in  this 
respect. 

"When  O.  H.  and  Bessemer  machine  steel  was  first  introduced 
it  was  poorly  made  and  hard  to  work.  Users  constantly  urged 
the  makers  to  make  it  softer,  until  when  a  maker  could  say  his 
steel  was  as  soft  as  iron,  and  not  more  than  o.io  to  0.15  of  i  per 
cent,  carbon,  he  had  the  market.  This  company  found  out  early 
that  this  soft  machine  steel  was  almost  worthless.  A  shaft  would 
bend  easily  in  working,  and  if  a  lead  screw  was  to  cut  it  was  not 
possible  to  get  a  smooth  thread  and  a  good  finish. 

"Now  we  either  make  shafts  and  spindles  of  cast  steel  of  a 
high  carbon  or  of  machine  steel  of  about  50  per  cent  carbon,  with- 
out annealing.  Our  men  kicked  at  first,  but  now  they  complain 
if  it  is  soft,  because  they  cannot  cut  a  good  thread  and  cannot  keep 
it  as  true." 

Re-Annealing   Tap   Blanks. 

Often,  from  improper  annealing,  a  tap  blank  proves  too  hard 
for  thread  cutting,  this  coming  about  in  the  annealing  processes, 
from  not  heating  properly  or  not  knowing  the  nature  of  the  steel. 
When  this  is  the  case  always  re-anneal  the  blank,  and  the  loss 
of  temper  and  wearing  out  of  good  tools  in  trying  to  cut  a  thread 
on  too  hard  stock  will  be  obviated.  Before  re-annealing  take  a 
rough  cut-off  and  clean  out  the  centers. 

How  to  Heat  for  Annealing. 

When  annealing  steel,  heat  very  slowly  to  a  red — never  heat 
it  hot  enough  to  raise  scale — and  allow  lots  of  time  for  cooling. 
A  piece  of  steel  heated  hot  enough  to  scale  will  never  work  well 
unless  re-annealed  by  some  method  which  will  restore  it  from  its 
almost  burnt  state. 


ANNEALING   PROCESSES.  43 

Annealing  a  Small  Quantity  of  Steel. 

When  only  a  small  quantity  of  steel  is  required  heat  to  a 
cherry  red  in  a  charcoal  fire  and  pack  in  sawdust  in  an  iron  box. 
Keep  the  steel  in  the  pack  until  cold.  For  a  large  quantity,  which 
is  required  to  be  very  soft,  pack  with  granulated  charcoal  in  an 
iron  box  as  follows :  Having  at  least  %  or  y\  inch  in  depth  of 
charcoal  in  the  bottom  of  the  box,  add  a  layer  of  granulated  char- 
coal to  fill  spaces  between  the  steel,  and  also  l/2  or  }4  inch  space 
between  the  side  of  the  box  and  the  steel,  then  more  steel,  and 
finally  i  inch  in  depth  of  charcoal  well  packed  on  top  of  the  steel. 
Heat  to  a  red  and  hold  for  from  two  to  three  hours  and  do  not 
remove  the  steel  from  the  box  until  cold. 

Annealing  Steel  in  the  Open  Fire. 

Although  the  annealing  of  steel  can  be  best  accomplished  by 
some  of  the  regular  packing  materials,  there  are  cases,  such  as  an 
emergency  job,  when  this  cannot  be  resorted  to,  because  of  the 
time  necessitated.  When  a  piece  of  annealed  steel  is  wanted  in  a 
hurry,  try  heating  in  an  open  fire  and  water  annealing — heating 
in  a  charcoal  fire  to  a  dull  red,  then  letting  the  steel  cool  natur- 
ally in  the  day  light  until  the  red  disappears,  and  then  quenching 
in  cold  water. 

Quick  Methods  for  Softening  Steel. 

In  the  following  we  give  a  few  methods  for  the  quick  anneal- 
ing of  steel,  gathered  from  various  sources : 

Cover  over  with  tallow,  heat  to  a  cherry  red  in  a  charcoal  fire 
and  allow  it  to  cool  itself. 

Heat  the  steel  to  a  low  cherry  red  and  allow  to  cool  in  a  dark 
place  until  black.  Then  quench  in  the  juice  or  water  of  common 
"beans. 

Cover  with  clay,  heat  it  to  a  cherry  red  in  a  charcoal  fire  and 
allow  to  cool  slowly. 

To  Anneal  Doubtful  Steel. 

There  are  some  kinds  of  steel  which  will  not  anneal  satisfac- 
torily even  when  packed  in  air-tight  boxes  in  powdered  charcoal. 
To  anneal  steel  of  this  kind,  cover  it  with  fine  clay  and  heat  to 
a  red  heat  and  allow  it  to  cool  over  night  in  the  furnace. 

Annealing  Chilled  Cast-Iron  Dies  for  Drilling. 
As  drawing  and  forming  dies  are  often  made  of  chilled  cast 


44  HARDENING,    TEMPERING    AND   ANNEALING. 

iron,  and  as  not  infrequently  holes  are  required  to  be  drilled  in 
them,  it  is  well  to  know  how  to  soften  it  to  allow  of  drilling  the 
holes.  To  do  this,  heat  the  die  to  a  cherry  red  and  let  it  lie  on 
the  coals.  Then  place  a  piece  of  brimstone,  circular  in  shape  and 
a  little  larger  in  diameter  than  the  hole  to  be  drilled,  on  the  spot 
where  the  hole  is  to  be.  Let  the  die  lie  in  the  fire  until  it  has  died 
out  and  the  metal  has  cooled,  and  the  brimstone  will  have  softened 
the  iron  entirely  through  within  the  radius  of  its  diameter  when 
solid. 

Annealing  White  or  Silver  Iron. 

To  anneal  white  or  silver  iron  so  that  it  may  be  drilled  or 
chipped,  put  it  into  a  steel  furnace  or  other  converting  furnace 
together  with  a  suitable  quantity  of  ironstone,  iron  ore,  some  of 
the  metallic  oxides,  lime,  or  any  other  combination  of  these  sub- 
stances reduced  to  a  powder,  or  any  other  substance  capable  of 
combining  with  or  absorbing  the  carbon  of  the  crude  iron.  The 
more  or  the  longer  the  heat  is  applied,  the  more  nearly  malleable 
the  iron  will  become. 

The  Annealing  of  Malleable  Castings  and  the  Manufacturing  of 

Malleable  Iron  Machine  Parts. 

One  of  the  largest  establishments  in  this  country  devoted  to 
the  manufacture  of  malleable  iron  machine  parts,  is  situated  in 
Hoosick  Falls,  N.  Y.,  and  is  controlled  by  the  Walter  A.  Wood 
Mowing  and  Reaper  Machine  Company.  A  description  of  their 
plant,  methods,  etc.,  will  tend  to  an  intelligent  understanding  of 
how  malleable  iron  machine  parts  are  produced. 

The  Foundry  and  Preparation  of  the  Castings. 

The  malleable  department,  exclusive  of  its  sheds,  has  a  floor 
space  of  over  163,000  square  feet,  the  foundry  alone  measuring 
485  x  125  feet.  In  this  department,  in  which  350  men  are  em- 
ployed, of  whom  135  are  molders,  there  are  three  furnaces  with  a 
capacity  of  three  heats  each  in  a  twelve-hour  day.  The  largest 
furnace,  almost  at  the  entrance  of  the  foundry,  will  melt  fourteen 
tons  of  metal  at  each  heat,  while  the  other  two  in  the  center  of 
the  foundry  and  at  the  extreme  end,  respectively,  will  each  melt 
ten  tons. 

The  castings  produced  are  mostly  of  small  size  and  are  made 
from  gated  patterns.  After  they  have  been  removed  from  the 
molds  they  are  broken  from  the  gates  and  are  sent  to  the  preparing 


ANNEALING   PROCESSES.  45 

department,  where  they  are  sorted,  and  all  lumps,  fins  and  gate 
joints  are  removed.  The  castings  as  they  come  from  the  molds  are 
almost  as  brittle  as  glass  and  it  is  possible  to  split  or  break  them 
with  a  light  blow  of  a  hammer.  It  is  very  interesting  to  watch 
the  men  in  this  operation.  They  can  take  a  casting,  set  the 
edge  or  lump  to  be  removed  on  an  iron  block  and  break  it  off 
at  the  joint  with  one  blow,  leaving  the  portion  where  the  joint 
was  as  smooth  as  the  rest  of  the  casting. 

Annealing  Furnaces — Packing  the  Castings. 
After  the  castings  have  been  sorted  and  prepared  they  go  to 
another  department  to  be  packed  into  the  annealing  pots.  These 
pots  are  cast,  and  are  about  24  inches  long,  12  inches  deep  and 
12  inches  wide,  and  an  inch  thick.  A  mixture  consisting  of 
common  sand,  fine  steel  turnings  and  steel  scale  from  the  rolling 
mills  is  then  wet  with  sal-ammoniac  (which  prevents  the  steel 
turnings  and  scale  from  adhering  to  the  castings  during  the  an- 
nealing process)  and  packed  around  the  castings  in  the  annealing 
pots.  The  pots  are  now  taken  to  the  annealing  room.  In  this 
room  there  are  eight  ovens,  the  walls  of  which  are  three  feet 
thick  and  the  tops  and  bottoms  four  feet  thick.  To  build  each  of 
these  ovens  4,500  red  brick  and  1,500  white  or  firebrick  were  re- 
quired. In  each  oven  there  are  flues  three  feet  square,  running 
the  full  length  of  the  oven  and  out  into  the  stack  at  one  end. 
There  is  also  one  intermediate  flue,  and  a  flue  at  each  side  into 
which  the  crude  oil  blast  is  fed. 

Different  Methods  of  Packing  Castings  in  Pots. 
There  are  various  methods  for  packing  castings  for  annealing. 
The  term  "packing"  is  a  shop  One  applied  to  the  class  of  materials 
which  are  used  for  the  above  purpose,  and  in  addition,  supply 
oxygen  or  have  the  latter  in  their  composition.  A  number  of 
different  materials  are  used  for  the  former  purpose  which  are 
'used  principally  on  lighter  castings.  Almost  anything  that  will 
stand  up  well  while  hot  is  suitable,  like  ground  burned  fire  brick, 
iron  borings,  and  sand.  As  they  of  themselves  do  not  supply 
oxygen,  it  is  necessary  in  using  them  that  oxygen  be  obtained 
by  means  of  a  coating  of  rust  or  oxide  upon  the  castings  either 
before  or  after  charging  the  pots.  In  rusting  them  before,  much 
of  the  oxide  becomes  rubbed  off  in  packing.  Packing  the  cast- 
ings wet  will  do,  provided  there  is  some  certainty  of  their  being 


46  HARDENING,    TEMPERING   AND    ANNEALING. 

oxidized  before  heating.  Wetting  the  packing  with  diluted  am- 
monia is  a  very  sure  means,  and  is  the  most  satisfactory  way  of 
handling  this  material. 

Packing  or  charging  castings  in  the  pots,  so  that  they  retain 
their  shape  and  do  not  scale  or  warp  while  hot,  is  a  process  that 
cannot  be  well  described.  In  general,  they  should  be  packed 
with  a  view  to  keeping  the  packing  in  close  contact  with  the 
castings  during  the  settling  of  the  contents  of  fhe  pot.  For  in- 
stance, flat  plates  or  sections  should  be  packed  on  edge ;  if  on  the 
side,  they  will  scale  on  the  bottom,  from  which  the  packings  have 
settled.  This  explains  why  some  castings  scale  and  others  da 
not  in  the  same  pot.  Castings  having  projections  or  unequal 
sides,  which  can  therefore  be  stacked  on  top  of  each  other,  are 
built  up  from  the  bottom  plate  with  a  view  to  balancing  the  pile. 
All  long  sections  and  long  castings,  unless  packed  in  pots  that 
will  admit  of  their  being  placed  horizontal,  should  be  set  upon 
the  bottom  plate  vertically.  I  have  seen  castings  5  feet  long 
become  y^  inch  longer  than  the  pattern,  because  they  were  packed 
some  inches  above  the  bottom  plate  and  hung  in  the  pot  during- 
settling.  As  a  general  rule,  there  is  a  relation  between  the  amount 
of  the  packing  and  the  castings,  or  between  the  oxygen  in  the 
packing  and  the  carbon  in  the  castings ;  there  can  therefore  be  a 
condition  where  there  is  not  sufficient  packing  between  the  cast- 
ings to  anneal.  There  should  always  be  an  excess  in  favor  of  the 
packing.  The  packing  of  the  castings  is  carried  upward  with  a 
view  to  meeting  the  unequal  heating  of  the  pots — that  is,  heavy 
castings  in  the  top  and  light  ones  in  the  bottom,  separated  by 
plates  when  the  occasion  requires  it.  Beginning  \vith  the  bottom 
plate,  the  first  pot  is  usually  a  new  one.  They  do  not  take  the 
heat  readily,  on  account  of  the  sand  upon  them,  and  for  this 
reason  should  be  broken  in  on  top.  Owing  to  their  weight,  how- 
ever, it  is  not  practical  to  use  them  there.  Building  or  packing 
continues  upward,  the  pots  being  placed  according  to  their  age, 
the  top  pots  passing  through  the  service. 

Annealing,  Straightening  and  Finishing  of  Malleable  Castings. 
In  the  malleable  department  of  the  Wood  works,  in  each  an- 
nealing oven,  pots  containing  twenty  tons  of  castings  are 
packed  as  close  together  as  possible,  after  which  the  vents  and 
doors  are  sealed  up  and  the  ovens  are  heated.  It  requires  twen- 
ty-four hours  of  steady  blast  to  get  the  ovens  and  castings  to  a 


ANNEALING   PROCESSES.  47 

white  heat.  They  are  then  kept  at  that  temperature  for  five  days 
and  five  nights,  after  which  the  blasts  are  turned  off  and  the 
vents  at  the  tops  of  the  ovens  opened.  After  the  vents  have  been 
open  for  five  hours  the  door  is  pulled  down  and  five  hours  later  the 
nearest  pots  are  removed,  and  in  the  course  of  a  few  hours  the 
others  are  taken  out  and  allowed  to  cool.  They  are  then  dumped 
and  the  castings  are  sorted.  All  that  have  cracked  or  blistered 
or  have  warped  excessively  are  thrown  out.  The  good  castings 
are  then  sent  to  the  straightening  department  to  be  straightened 
and  reformed,  so  as  to  fit  the  jigs  and  fixtures  which  are  used 
for  machining  those  which  are  required  to  be  machined  and  to 
make  the  others  interchangeable.  The  straightening  and  re- 
forming of  the  castings  are  accomplished  by  dies  in  powerful 
presses.  There  are  seven  different  machines,  one  a  hydraulic 
press  of  seven  tons,  one  five-ton  power  press,  and  two  powerful 
drop  hammers.  On  shelves  surrounding  the  straightening  room 
are  hundreds  of  sets  of  dies.  The  dies  for  the  large  castings  are 
of  gray  iron,  while  those  for  the  small  parts  are  of  hard  iron. 
The  dies  are  cast  in  the  department's  own  foundry  by  first  getting 
a  plaster  model  of  the  inside  of  the  master  patterns  and  one  of 
the  outside  and  then  casting  the  dies  from  this  model. 

After  the  straightening  and  re-forming  process,  the  castings 
are  sent  to  the  grinding  and  finishing  department.  Here  all 
lumps  and  fins  which  were  not  removed  before  the  annealing  are 
ground  off.  The  parts  to  be  machined  are  finished  in  special 
jigs  and  fixtures  on  the  drill  press,  milling  machine  or  lathe,  as 
most  suitable,  and  the  castings  are  then  ready  for  the  storeroom. 

As  every  size  and  style  of  casting  produced  in  the  foundry  is 
numbered,  and  as  the  numbers  run  from  i  to  2,503,  some  idea  may 
be  formed  of  the  storage  space  required.  The  patterns  used  are 
of  composition  metal.  They  are  stored  in  a  fireproof  vault,  65 
by  25  feet  and  12  feet  high. 

Heating  the  Annealing  Ovens. 

To  heat  the  annealing  ovens,  crude  petroleum  is  used,  the  oil 
being  pumped  from  three  tanks  sunk  in  the  ground  300  feet  from 
the  ovens  and  200  feet  from  the  engine-room  in  which  pumps  are 
located.  One  tank  holds  13,000  gallons  of  oil  and  the  other  two 
6  ooo  gallons  each.  The  large  tank  is  located  beneath  the  rail- 
road track  and  is  filled  from  tank  cars,  and  this  in  turn  fills  the 
small  ones.  The  pump  used  to  pump  the  oil  to  the  annealing1 


48  HARDENING,    TEMPERING   AND   ANNEALING. 

ovens  runs  continually  and  has  not  been  shut  down  twelve  hours 
in  a  year.  To  melt  the  iron  used  in  the  malleable  iron  foundry 
soft  coal  is  used,  the  furnaces  being  so  constructed  as  to  allow 
of  the  coal  being  placed  in  the  front  part  and  the  metal  and  other 
materials  required  to  produce  hard  iron  at  the  back,  the  heat 
being  driven  in  on  the  mixture  by  air  pressure. 

General  Matter  Relative  to  Malleable  Iron  Manufacturing. 

Mr.  Robert  Leith,  the  superintendent  of  the  department,  has 
been  with  the  Wood  Company  for  twenty-five  years,  and  has  been 
responsible  for  the  many  innovations  in  his  department  tending 
to  economic  production,  one  of  which  is  to  use  in  his  foundry  all 
cf  the  scrap  steel  produced  in  the  main  works.  He  has  used  100 
pounds  of  the  scrap  steel  to  every  ton  of  iron,  and  has  secured  the 
very  best  of  results  by  so  doing.  Formerly  it  was  necessary  to 
sell  the  scrap  steel  for  almost  nothing,  in  comparison  with  its 
cost  to  the  firm,  but  now  the  malleable  department  disposes  of 
all  of  it.  The  output  from  the  malleable  department  per  week 
is  usually  150  tons  of  good  castings,  the  bad  work  coining  from 
the  foundry  and  annealing  department  not  being  counted.  The 
power  required  for  the  department  is  derived  from  a  150  horse- 
power engine,  which  has  been  in  use  over  twenty-five  years,  and  is 
to-day  a  fine  example  of  what  care  and  a  good  engineer  can  do 
for  an  engine  in  regard  to  its  longevity. 

On  the  harvesting  machinery  manufactured  by  the  Wood 
Company  a  great  deal  of  chain  is  used.  The  links  composing 
these  chains  are  produced  in  the  malleable  department  and  the 
chains  are  assembled  and  finished  there.  The  links  are  cast  from 
gated  patterns,  as  many  as  fifty  links  to  each  mold.  The  gating 
is  done  in  such  a  manner  that  when  the  castings  have  been 
broken  from  the  gate  bars  very  little  irregularity  of  surface  is 
evident;  what  projections  remain  are  ground  off  after  the  anneal- 
ing process.  The  chains  are  assembled  in  continuous  lengths  by 
an  automatic  machine,  the  links  being  fed  through  a  chute  at  the 
front  and  the  chain  fed  out  automatically  at  the  back.  The 
chains  are  subjected  to  various  tests  to  insure  their  being  the 
length  required.  Often  (as  the  links  are  not  machined  before  as- 
sembling) some  of  the  chains  will  be  shorter  than  required,  this 
coming  about  through  unequal  rapping  when  molding,  etc.,  the 
part  where  the  links  unite  being  thicker  in  some  than  in  others, 
the  accumulation  in  the  course  of  a  number  of  links  making  quite 


ANNEALING   PROCESSES.  49 

a  difference  in  the  length  of  the  chain.  This  defect  is  overcome 
by  means  of  another  machine,  in  which  the  chains  are  stretched 
until  they  are  of  the  required  length. 

There  is  a  metal  pattern  shop  connected  with  the  department 
ir>  which  all  the  patterns  used  in  the  foundry  are  finished.  In 
this  shop  some  of  the  finest  metal  pattern-work  that  I  have  ever 
seen  is  turned  out,  as  is  evidenced  by  the  fact  that  out  of  a  thou- 
sand castings  of  a  certain  shape  only  two  were  found  to  be  "off" 
enough  to  prevent  their  being  machined  in  the  fixtures  provided 
for  them.  Besides  producing  all  the  malleable  castings  which 
the  works  require,  the  department  also  does  custom  work,  and  it 
has  the  reputation  of  having  done  some  of  the  finest  work  in  the 
country. 


CHAPTER  III. 

THE     HEATING    AND    COOLING    OF    STEEL LOCATION     OF     HEATING 

ARRANGEMENTS THE     USE     OF     GAS     BLAST     FURNACES     AND 

HEATING    MACHINES TOUGH    STEEL    AND    HARD    STEEL;    THE. 

DIFFERENCE. 

The  Heating  and  Cooling  of  Steel. 

There  are  any  number  of  shops  in  which  a  great  deal  of  un- 
necessary expense  is  incurred  in  the  annealing,  hardening  and 
tempering  of  steel  through  improper  heating  and  cooling  during 
the  processes ;  and  while  often  inexperience  is  the  cause  of  such 
expense,  more  often  the  crude  and  obsolete  means  employed  for 
heating  and  cooling  are  to  blame. 

The  fact  is  obvious  to  all  that  where  expensive  tools  are 
made,  proper  facilities  should  be  provided  for  the  heating  proc- 
esses through  which  they  are  put.  If  there  is  any  economy  in 
providing  fine  machine  tools  and  employing  skilled  mechanics 
to  make  fine  small  tools  and  utterly  ignoring  the  requirements  for 
the  annealing  and  tempering  of  them,  we  fail  to  see  it. 

Now,  while  a  plain  ordinary  forge  is  all  right  and  will  be 
found  to  be  all  that  is  necessary  for  the  annealing  and  tempering 
of  rough  tools,  it  will  not  do  for  fine  ones.  When  it  is  considered 
that  an  accurate  cutting  tool  which  has  been  annealed  properly 
before  finishing,  and  then  carefully  and  accurately  hardened  and 
tempered  afterward,  will  accomplish  many  times  the  amount  of 
work  that  an  imperfectly  treated  one  will,  the  expense  incurred 
in  providing  suitable  heating  facilities  is  insignificant,  when  the 
longevity  of  the  tools  treated  is  considered.  In  shops  where  a 
fair  number  of  fine  cutting  tools  are  made  and  used,  the  cost  of 
proper  heating  arrangements  will  be  made  up  in  a  short  time  by 
the  money  saved  through  the  use  of  properly  hardened  and  tem- 
pered tools.  Another  thing:  after  having  installed  a  suitable 
hardening  plant,  hire  a  mechanic  to  run  it  who  understands  the 
treatment  of  steel.  With  this  combination,  and  a  supply  of  good 
high-grade  steel,  there  will  be  no  dissatisfaction  with  the  working 
qualities  of  the  cutting  tools ;  if  there  is,  there  will  be  no  excuse 
for  it ;  carelessness  will  be  to  blame. 


HEATING   STEEL GAS   BLAST    FURNACES. 


FIG.  25. — TYPES  OP  EXPENSIVE  MILLING  CUTTERS. 


52  HARDENING,    TEMPERING    AND    ANNEALING. 

The  only  way  to  heat  steel  properly  and  thoroughly  is  to  not 
expose  it  to  the  action  of  air  when  hot,  as  the  air  will  decarbonize 
the  surfaces  considerably.  Thus,  when  steel  is  heated  in  a  muffle 
furnace  an  even  degree  of  heat  is  assured  and  all  air  is  excluded. 

Proper  Equipment  for  Hardening  and  Tempering. 

The  proper  equipment  for  annealing,  hardening  and  temper- 
ing tools  of  different  types  can  be  decided  by  noting  the  various 
descriptions  for  obtaining  the  best  results  given  in  this  and  other 
chapters  of  the  book.  A  number  of  types  of  furnaces,  mufflers 
and  other  arrangements  are  shown  in  this  chapter  and  their  use 
and  adaptation  for  different  classes  of  work  explained. 

Points  to  be  Remembered. 

To  heat  and  cool  steel  properly,  remember  the  following : 
Never  heat  a  piece  of  steel  which  is  to  be  annealed  above  a  bright 
red.  Never  heat  a  piece  to  be  hardened  above  the  lowest  heat  at 
which  it  will  harden,  and  the  larger  the  piece  the  more  time  re- 
quired to  heat  it  is  required,  which  will  have  to  be  higher  than  a 
smaller  piece  of  the  same  steel,  because  of  the  fact  that  a  large 
piece  takes  longer  to  cool  than  a  smaller  piece,  as  when  a  large 
piece  of  steel  is  plunged  into  the  bath  a  large  volume  of  steam 
arises  and  blows  the  water  away  from  it,  thus  necessitating  more 
time  in  the  cooling.  Thus,  when  the  tool  or  die  is  very  large,  a 
tank  should  be  used  to  harden  it  in,  into  which  a  stream  of  cold 
water  is  kept  constantly  running,  as  otherwise  the  red  hot  steel 
will  heat  the  water  to  such  a  degree  that  the  steel  will  remain 
soft. 

The  Location  of  the  Heating  Furnace. 

Although  in  a  great  many  shops  very  little  importance  is 
attached  to  the  proper  placing  and  locating  of  the  furnace  which 
is  to  be  used  during  the  hardening  processes,  it  will  be  found  that 
if  the  location  chosen  is  in  a  darkened  corner  where  the  sun's 
rays  will  not  come  near  it,  the  best  results  will  be  attained.  No 
matter  what  kind  of  hardening  is  to  be  done,  the  heating  arrange- 
ments should  never  be  located  where  there  is  too  strong  a  light, 
or  where  the  sun  shines  in  at  any  time  of  the  day.  If  the  light 
is  uniform  it  will  not  be  difficult  to  attain  uniform  results,  while, 
on  the  contrary,  if  the  light  is  too  bright,  there  is  a  chance  of 
heating  the  steel  too  hot  and,  when  it  becomes  darker,  not  hot 


HEATING  STEEL — GAS  BLAST   FURNACES.  53 

enough.  When  a  uniform  light  is  maintained  during  the  day  the 
men  become  accustomed  to  it  and  no  trouble  is  experienced  in  get- 
ting the  best  of  results. 

The  Use  of  Gas  Blast  Furnaces  and  Heating  Machines. 

The  use  of  gas  blast  furnaces  and  heating  machines  has  now 
become  so  extensive  as  to  have  almost  completely  superseded  the 
old  methods,  and  the  furnaces  and  machines  are  now  used  in  se- 
curing the  highest  possible  efficiency  in  the  use  of  heat  for  me- 
chanical purposes  as  well  as  in  the  processes  of  metallurgy  and 
chemistry. 

Gas  blast  furnaces  are  designed  for  the  economical  use  of  gas 
as  fuel  in  forges,  crucible  furnaces,  annealing,  enameling,  case- 
hardening  ovens,  assaying,  cupeling  and  other  muffle  furnaces, 
japanning  ovens,  and  drying  and  baking  kilns,  in  all  of  which 
the  heat  is  generated  by  a  properly  proportioned  mixture  of  gas 
and  air,  injected  under  positive  pressure,  through  burners  espe- 
cially adapted  to  each  of  the  different  kinds  of  gas  in  common 
use. 

Heating  machines  may  be  called  "modern  machine  tools," 
made  for  special  heating  processes,  as  they  are  combinations  of 
gas  furnaces  and  moving  machinery  for  the  automatic  feeding 
and  discharging  of  work  which  is  to  be  annealed,  hardened,  tem- 
pered or  forged  in  quantities. 

The  chief  advantages  derived  from  the  use  of  gas  as  a  fuel  are 
the  perfect  adjustment  of  temperatures  to  suit  exact  require- 
ments, which  is  impossible  with  either  solid  or  liquid  fuel ;  the 
ease  with  which  any  desired  degree  of  heat  can  be  obtained  by 
simple  adjustments  of  two  valves,  the  uniformity  of  its  distri- 
bution within  given  space,  the  partial  or  complete  absence  of  oxida- 
tion, and,  generally,  the  perfectly  uniform  condition  under  which 
any  heating  process  can  be  performed  irrespective  of  the  quanti- 
ties of  work  to  be  heated. 

The  gas  consumption,  cost  of  gas  as  compared  with  other 
fuel,  while  an  important  factor  in  determining  the  adoption  of 
gas  furnaces  for  the  cruder  operation  of  melting  or  forging, 
scarcely  deserves  consideration  with  reference  to  furnaces  or 
heating  machines  for  hardening,  tempering  or  annealing  large 
quantities  of  work,  because  no  approximately  equal  amount  of 
perfect  work  can  be  produced  by  the  use  of  any  other  fuel  than 
gas. 


54  HARDENING,    TEMPERING   AND    ANNEALING. 

Gas  Blast  Forges — Their  Use. 

Gas  blast  forges  heat  the  work  quickly,  uniformly,  and  with 
little  or  no  scale.  They  are  always  ready  for  use  and  develop 
the  required  amount  of  heat  in  a  few  minutes.  They  are  used  in 
machine  shops  for  tool  dressing  and  forging ;  in  the  production  of 
quantities  of  small  forgings,  such  as  cutlery,  and  for  drop  forg- 
ings  generally. 

While  offering  decided  advantages,  no  single  gas  forge  or 
furnace  can  replace  the  ordinary  coal  forge  in  everything,  because 
to  be  thoroughly  effective,  as  well  as  economical  in  gas  con- 
sumption, the  gas  forge  must  be  made  for  a  definite  range  of 
work,  and  its  heating  space  limited  so  as  to  conform  to  its  size 
and  shape,  with  only  fair  allowance  for  clearance  space. 

In  order  to  determine  the  applicability  of  any  of  the  various 
styles  of  gas  forges  now  on  the  market,  the  dimensions  of  the 
entrance,  height,  width,  depth,  and  length  of  the  heating  chamber 
must  be  considered,  and  a  fair  allowance  made  for  clearance. 
When  samples  of  work  to  be  done  are  furnished  to  the  manu- 
facturers of  such  machines,  together  with  a  statement  of  the 
quantities  to  be  heated  in  any  given  time,  they  will  design  special 
forges. 

When  gas  blast  forges  are  used  in  forging  the  overheating  of 
the  metal  is  entirely  prevented,  a  non-oxidizing  atmosphere  re- 
ducing the  scale  to  a  minimum,  thus  supplying  properly  heated 
stock  as  fast  as  it  can  be  handled. 

For  welding,  special  forges  should  always  be  designed  for  any 
particular  kind  of  work,  so  that  the  blast  will  be  confined  closely 
to  the  joint  to  be  made.  In  welding  tires,  the  diameter,  width 
and  thickness  will  determine  the  shape  of  the  entrance  to  the  forge 
and  conform  to  it. 

Combination  Gas  Furnace  for  General  Machine  Shop  Work. 

In  Fig.  26  we  illustrate  a  combination  gas  furnace  ready  to 
operate. 

This  furnace  combines  on  one  base  three  most  useful  furnaces 
for  general  machine  shop  and  tool  work.  It  will  heat  quickly 
and  uniformly  any  piece  or  pieces  that  will  go  into  its  various 
openings.  The  muffle  can.  be  heated  to  a  good  heat  for  hardening 
in  from  ten  to  twelve  minutes  and  kept  at  the  desired  temperature 
indefinitely.  The  forge  will  heat  a  piece  I  inch  round  to  a  good 


HEATING  STEEL — GAS   BLAST   FURNACES. 


55 


hardening  heat  in  one  minute,  starting  with  the  furnace  cold. 
The  crucible  full  of  lead  can  be  heated  to  cherry  red  in  about 
thirty-five  minutes. 

A  furnace  of  this  type  occupies  very  little  room;  does  not 
require  to  be  connected  to  chimney;  can  be  placed  right  in  the 
tool  room  or  anywhere  it  is  most  convenient;  can  be  started  in- 
stantly, and  covers  a  range  of  uses  that  makes  it  practically  indis- 
pensable. All  sorts  of  small  tools,  such  as  dies,  milling  cutters, 


FIG.   26. — COMBINATION    GAS   FURNACE. 

reamers,  punches,  taps,  drills,  springs,  cutlery,  marking  rolls, 
etc.,  can  be  heated  in  the  muffle  under  the  best  possible  condi- 
tions. 

A  section  of  this  combination  furnace,  showing  the  muffle 
with  walls  cut  away  to  illustrate  arrangements  of  combustion 
chamber  and  muffle,  is  shown  in  Fig.  27. 

The  flame  is  projected  from  the  double  burners  downward  into 
the  chamber  encircling  the  muffle ;  the  lining  is  of  such  shape  that 
a  rotary  motion  is  imparted  to  the  flame,  causing  same  to  distri- 


56  HARDENING,    TEMPERING    AND    ANNEALING. 

bute  itself  evenly  all  over  the  inclosed  space ;    the  products  of 
combustion  are  drawn  off  by  the  two  small  openings  at  the  top  of 

the  chamber.  The  muffle  is 
heated  rapidly  and  evenly 
throughout;  the  degree  of  heat 
is  under  perfect  control;  the 
work  is  absolutely  secluded  from 
the  products  of  combustion,  a 
feature  of  the  greatest  import- 
ance in  heating  dies,  milling  cut- 
ters and  other  expensive  tools. 
Absolute  uniformity  can  be 
maintained;  overheating  can  be 
entirely  avoided,  difficult  pieces 
can  be  hardened  without  danger 
of  cracking  by  reason  of  an  even 
heat  throughout. 

Every    manufacturer     whose 
product   involves   the  machining 


FIG.  27. — SECTION  OF  FURNACE 
CONTAINING  MUFFLE,  SIZE 
5x8x15  INCHES. 


FIG.   28. — FORGE  SECTION    OF   FURNACE.       SIZE   OF   OPENING, 
INCHES.       LENGTH,    14   INCHES. 


HEATING   STEEL GAS   BLAST   FURNACES. 


57 


of  metals  realizes  the  necessity  of  having  modern  apparatus  for 
systematically  applying  heat,  the  output  of  his  entire  plant  depend- 
ing quite  as  much  on  the  temper  of  his  tools  as  on  any  other  one 
condition.  To  get  good  results  from  tools  use  good  steel  and 
harden  and  temper  it  properly  and  the  result  will  invariably  be 
satisfactory. 

The  forge  section  of  this  furnace  is  shown  in  Fig.  28. 

The  combustion  chamber  is  circular  in  form  and  is  heated 


FIG.   29. — CRUCIBLE   SECTION   OF  FURNACE. 

by  two  burners  which  project  the  flame  downward,  the  form  of 
the  lining  giving  the  flame  a  rotary  motion,  evenly  distributing 
it  all  over  the  chamber.  The  heat  is  under  perfect  control.  This 
forge  is  very  convenient  for  dressing  and  hardening  tools  and 
small  forgings  and  for  a  variety  of  work  where  seclusion  from  the 
products  of  combustion  is  not  required. 

In  Fig.  29  is  shown  the  crucible  section  of  the  furnace.     The 


5§  HARDENING,    TEMPERING   AND    ANNEALING. 

combustion  chamber  is  circular  in  form ;  burners  are  so  arranged 
that  the  flame  is  projected  into  the  chamber  without  striking  ti.^ 
crucible  direct.  A  rapid  centrifugal  motion  is  imparted,  dis- 
tributing the  heat  evenly  and  thoroughly.  The  products  of  com- 
bustion are  drawn  off  at  vent  in  the  rear. 

For  heating  a  great  variety  of  small  pieces  the  lead  bath  offers 
many  advantages  over  other  methods.  By  keeping  the  tempera- 
ture of  the  lead  at  the  proper  point,  overheating  is  impossible  and 
uniformity  is  secured.  Small  pieces  can  be  heated  very  rapidly 
by  this  method. 

For  tempering  a  crucible  (Fig.  30)  similar  to  the  one  used  for 


FIG.  30. — CRUCIBLE. 

the  lead  bath  is  filled  with  beef  tallow.  The  exact  heat  required 
to  temper  or  draw  the  work  is  easily  maintained  as  indicated  by 
a  thermometer,  which  should  be  suspended  in  the  bath.  For  all 
small  tools,  milling  cutters,  screw  springs,  punches,  dies,  etc.,  there 
is  no  method  of  tempering  (or  drawing)  so  satisfactory  as  this. 
Temperatures  that  have  been  found  to  give  the  best  results  can 
repeatedly  be  employed.  The  work  to  be  tempered  can  be  sus- 
pended in  the  liquid  tallow  by  means  of  a  wire  basket,  or  other 
convenient  method,  and  can  be  left  there  indefinitely  without  dan- 
ger of  the  temper  running  too  low ;  all  parts  of  the  piece  or  pieces 
immersed,  whether  of  thin  or  thick  section,  will  be  evenly 
heated. 


HEATING  STEEL GAS   BLAST   FURNACES, 


59 


Gas  Forge  for  Small   Work. 

The  gas  forge  shown  in  Fig.  31  is  of  a  type  commonly  used 
for  dressing  and  hardening  tools  and  smaller  forgings.  The 
heating  chamber  is  circular  inside,  and  its  capacity  is  limited  hr 


I 


FIG.  31. — GAS  FORGE.      ENTRANCE,  6  INCHES  WIDE  BY  3   INCHES 
HIGH  ;    DEPTH  OF  HEATING  SPACE,    6   INCHES. 

the  size  of  the  entrance  to  the  heating  chamber,  and  a  correspond- 
ing opening  in  the  back  is  ordinarily  closed  by  a  "plug,"  which 
can  be  removed  when  a  clear  passage  through  the  furnace  is  re- 


6o 


HARDENING,    TEMPERING   AND    ANNEALING. 


quired.  Two  burners  project  into  the  heating  chamber  from  the 
distributing  pipe,  D,  W,  so  adjusted  that  direct  contact  of  the 
flames  with  the  work  is  avoided.  Perfect  combustion  is  steadily 
maintained,  the  work  is  quickly  and  evenly  heated  and  oxidization 
reduced  to  a  minimum. 

The  furnace  is  connected  with  air  by  a  tin  pipe  at  B,  and  the 


FIG.  32. — GAS  FORGE  FOR  HEATING  DROP  FORGINGS. 

cock  A  controls  the  air  supply.  Gas  connects  with  union  from 
the  nearest  supply  pipe  by  ^4 -inch  pipe  at  P,  and  globe  valve  G 
controls  the  gas  supply.  The  small  cock  C  feeds  a  "pilot  light" 
in  the  mouth  of  the  furnace,  which  is  left  burning  so  as  to 
instantly  light  the  forge  when  the  main  supply  is  turned  on.  The 
bottom  of  the  furnace  can  be  cleaned  of  scaling  by  removing  a 
plug  which  is  held  in  place  by  the  set  screw  I,  which  passes 


HEATING   STEEL — GAS   BLAST   FURNACES.  6l 

through  the  hanger,  K.  The  air  relief  valve  R  is  a  test  valve  to 
show  the  air  pressure  at  the  furnace,  and  when  this  has  been  found 
sufficient  it  can  be  weighted  down  tight. 

Gas  Forge  for  Heating  Drop-Forgings. 

The  style  of  forge  shown  in  Fig.  32  is  extensively  used  for 
drop  forgings,  to  heat  blanks  continuously  and  keep  them  at  the 
proper  heat.  The  heating  space  is  10  inches  deep,  8  inches  wide 
and  3  inches  high.  The  burners,  B,  penetrate  the  chamber  from 
opposite  sides  and  the  flames  do  not  strike  the  work  direct.  The 
blanks  rest  upon  a  fire  brick  bottom,  which  is  removable  from  the 
rear  for  cleaning  out  the  chamber.  This  forge  is  extensively  used 
in  connection  with  oil  gas,  but  can  be  adapted  to  every  other 
kind. 

Air  Tempering  Furnace. 

Air  tempering  furnaces  of  the  type  shown  in  Fig.  33  are  used 
for  drawing  the  temper  of  steel  work  of  all  kinds,  but  more  espe- 
cially for  small  light  work  in  quantities.  While  cutters,  punches, 
dies  and  knife  blades  are  perfectly  tempered  in  heated  oil,  in  oil 
tempering  furnaces,  the  air  tempering  furnace  is  used  when  the 
oil  stain  is  objectionable,  or  when  it  is  desired  to  show  a  bright, 
clear,  temper  color  of  any  desired  shade,  from  a  light  straw  to  a 
blue  or  gray. 

The  furnace  contains  an  iron  muffle  with  a  horizontal  partition 
in  the  bottom  which  forms  an  air-heating  chamber  below  the 
level  of  the  entrance  into  which  the  air  is  forced  from  the  blower 
which  operates  the  furnace,  the  injection  of  which  is  controlled  by 
the  valve  H.  From  this  air  heating  chamber  the  heated  air  is 
distributed  through  numerous  fine  holes  so  as  to  keep  the  muffle 
filled  with  heated  air  under  a  slight  pressure,  which  is  exerted 
around  a  thermometer  stem  when  the  door  is  closed. 

The  burner  is  controlled  by  the  air  valve  A,  and  the  gas  valve, 
G.  The  connection  with  blower  is  to  the  drum,  D,  and  gas  is 
brought  to  the  gas  valve,  G.  The  burner  distributes  the  heat 
evenly  under  the  muffle  and  around  it,  so  that  the  atmospheric 
temperature  within  the  working  space  of  the  muffle  is  perfectly 
even  throughout. 

The  work  is  placed  upon  a  wire  tray  and  evenly  distributed 
over  its  surface,  and  is  constantly  subjected  to  the  action  of  fresh 
air  heated  to  the  proper  degree. 

The  tray  containing  the  work  rests  upon  the  open  grating 


62 


HARDENING,    TEMPERING   AND    ANNEALING. 


shown  in  the  cut,  which  is  raised  above  the  bottom  of  the  muffle, 
and  the  heated  air  is  forced  through  and  around  the  work  from 
the  perforated  heating  chamber,  thus  coming  in  contact  with 
freshly  heated  air  constantly. 

The  operation  is  as  follows : 

It  will  require  about  40  minutes  to  heat  a  furnace  of  this  type 


FIG.  33. — AIR  TEMPERING  OVEN. 


to  the  600  deg.  required  for  a  blue  temper.  This  temperature 
being  indicated  by  the  thermometer,  the  work  is  inserted  and  the 
door  closed.  The  thermometer  will  then  show  a  decided  decrease 
in  temperature  due  to  the  absorption  of  the  heat  by  the  work. 
After  lapse  of  a  certain  time,  determined  by  the  weight  of  the 


HEATING   STEEL GAS   BLAST   FURNACES.  63 

charge,  the  temperature  will  commence  to  rise  again,  and  when 
it  gets  back  to,  say,  600  deg.,  where  the  thermometer  stood  when 
the  work  was  inserted,  the  work  is  promptly  removed. 

It  should  be  remembered  that  the  thermometer  will  not  indicate 
the  precise  temperature  at  which  steel  reaches  a  certain  temper 
color  under  other  conditions,  but  the  temperature  at  which  work 
will  reach  the  exact  temper  color  desired  being  once  noted,  the 


FIG.  34. — GAS  FORGE  FOR  KNIFE  AND  SHEAR  BLADES. 


64 


HARDENING,    TEMPERING   AND   ANNEALING. 


furnace  will  perform  the  same  work  with  the  same  degree  of  heat 
in  the  same  time,  so  that  the  operator  will  then  be  able  to  turn 
out  successive  charges  by  simply  watching  the  thermometer  and 
a  clock. 

Gas  Forge,  for  Knife  and  Shear  Blades. 

The  construction  of  the  furnace  shown  in  Fig.  34  is  similar  to 
that  of  an  oven  furnace,  but  the  firebrick  slab  upon  which  the 
work  rests  is  ridged.  These  ridges  form  the  partitions  for  the 


FIG.  35. — BENCH  FORGE. 

heating  of  each  blade  separately.  The  slab  is  as  wide  as  the  en- 
trance, and  does  not  extend  to  the  rear,  but  leaves  a  narrow  slot 
through  which  the  heat  is  forced  from  under  the  slab  upward 
around  the  rear  end  of  the  slab  and  then  forward  in  even  volume 
to  the  vent,  E,  over  the  entrance. 

In  order  to  protect  the  points  and  thin  ends  of  the  blades,  the 
corrugated  slab  may  be  covered  as  far  as  necessary  by  the  fire- 
brick slab,  F,  and  thus  heated  by  conductivity  rather  than  direct 
action  of  the  flame,  while  the  thicker  portions  of  the  blades  are 


HEATING  STEEL GAS   BLAST   FURNACES.  65 

directly  subjected  to  it.  The  difference  in  the  time  required  to 
heat  the  thin  and  the  heavier  portions  of  the  blade  is  thus  approxi- 
mately equalized,  and  the  whole  blade  heated  uniformly  to  the 
exact  degree  required. 

The  cut  represents  a  furnace  made  especially  for  shear  blades 
from  8  to  12  inches  long,  and  will  accommodate  12  blades  at  a 
time,  and  will  heat  blades  for  forging  or  hardening  as  fast  as 
they  can  be  conveniently  handled. 

Bench  Forge. 

The  bench  forge  shown  in  Fig.  35  is  a  handy  little  gas  forge 
to  be  placed  on  the  work  bench,  for  forging  and  tempering  small 
tools,  heating  the  ends  of  rods  or  small  pieces  of  metal  of  any 
kind.  The  heating  space  or  chamber  is  il/2  inches  wide  and 
high  and  3  inches  deep,  heated  evenly  throughout  by  two  side 
burners  whose  focus  is  in  the  center  of  the  slot.  Work  can  be 
placed  over  the  slot  and  heated  from  below,  or  the  slot  can  be 
covered  by  a  slab  shown  in  cut,  and  the  heat  confined  to  the 
chamber  and  raised  to  a  very  high  degree  quickly. 

The  forge  can  be  permanently  connected  with  gas  pipe  and  air 
supply,  or  by  rubber  hose  to  be  movable. 

Gas  is  supplied  through  ^s-inch  pipe,  varies  according  to 
work  done  and  quality  of  gas,  and  the  amount  consumed  is  too 
small  to  be  considered  when  its  work  is  taken  into  account. 

Oven  Furnaces  for  Annealing  and  Hardening. 

Oven  furnaces  are  used  to  heat  a  square  or  oblong  space  of  any 
desired  dimensions,  evenly  throughout,  to  any  required  degree  of 
heat  from  a  cherry  red  to  a  white  heat,  and  especially  to  main- 
tain any  required  temperature  steadily  for  any  desired  length 
of  time. 

They  will  do  the  work  of  muffle  furnaces  perfectly  except 
where  an  absolute  seclusion  of  the  work  from  the  products  of 
combustion  is  necessary.  They  are  used  for  heating  cutters,  dies, 
reamers,  shear  blades,  saws,  and  for  annealing  all  kinds  of  metal 
work  in  quantities. 

The  annexed  cut  of  oven  furnace,  Fig.  36,  is  typical  of  all  oven 
furnaces  except  dimensions  and  the  shape  of  entrance  high.  The 
entrance  closed  by  the  door,  E,  is  12  inches  wide  and  6  inches 
high.  The  firebrick  slab,  S,  separates  heating  chamber  above  it. 

The  slab,  S,  covers  the  full  length  of  the  heating  chamber  from 


66 


HARDENING,,    TEMPERING    AND    ANNEALING. 


front  to  rear,  and  is  supported  by  small  angle  bricks  located  be-1- 
tween  the  burners  so  as  not  to  obstruct  them. 

The  width  of  the  slab  is  less  than  that  of  the  interior  of  the: 
chamber,  so  that  a  slot  is  formed  between  the  edges  of  the  slab 


FIG.  36. — OVEN   FURNACE   FOR   HARDENING   AND   ANNEALING. 

and  the  side  walls  of  even  width  throughout.  The  burners,  C,, 
bolted  to  the  distributing  channel,  B,  are  transposed  with  refer- 
ence to  the  opposite  series  of  burners,  and  arranged  so  that  the 
injected  flames  pass  one  another  in  opposite  directions  alter- 
nately. The  injection  of  the  fuel  under  pressure  forces  the  heat 


HEATING   STEEL GAS   BLAST    FURNACES.  6/ 

through  the  slots  on  each  side  of  the  slab,  S,  into  the  heating 
chamber  above  it,  in  even  volume,  and  when  the  combustion  cham- 
ber under  the  slab,  S,  has  been  heated  up,  the  heat  rapidly  accumu- 
lates in  the  heating  chamber.  The  products  of  combustion  are 
released  by  the  vent-holes,  V,  which  being  in  the  center,  draw 
the  heat  upward  from  both  sides,  thus  thoroughly  heating  the 
roof  of  the  oven,  from  which  the  heat  is  reflected  downward. 

By  the  proportionate  arrangement  of  all  parts  of  the  construc- 
tion the  heated  chamber  is  evenly  heated,  and  a  block  of  steel 
placed  as  shown  in  the  cut,  will  be  heated  up  with  perfect  even- 
ness simultaneously  from  all  sides.  The  vestibuled  entrance 
materially  lessens  the  cooling-off  effect  produced  by  the  opening 
door,  E. 

The  gas  supply  and  burners  can  be  readily  adjusted  so  that  no 
flame  whatever  will  be  visible  in  the  heating  chamber,  but  as  this 
would  conduce  to  oxidation,  the  proportion  of  gas  is  indicated 
when  a  very  small  flame  issues  from  the  vent,  V,  after  the  furnace 
has  become  thoroughly  heated.  For  all  metal  work  the  at- 
mosphere in  the  heating  chamber  should  be  just  visible  by  a 
''flimmering"  effect,  which  indicates  a  non-oxidizing  atmosphere. 

The  advantages  of  an  oven  furnace  over  a  "muffle"  consist 
in  the  more  immediate  and  direct  action  of  the  heat  upon  the 
work,  the  lessened  running  expense  by  dispensing  with  costly  and 
perishable  muffles,  and  the  adaptability  of  this  furnace  to  very 
much  larger  work. 

Case-Hardening  Furnaces. 

Case-hardening  furnaces  of  the  type  shown  in  Figs.  37  and  38 
are  oven  furnaces  in  construction,  but  being  intended  for  work 
requiring  the  continuous  application  of  higher  heat,  the  linings 
are  much  heavier,  and  the  entrance  is  closed  by  solid  firebrick 
plugs,  P,  which  are  inserted  and  withdrawn  by  the  cast  iron  car- 
riers, D.  As  their  name  indicates  they  are  mainly  used  for  the 
process  of  case-hardening  in  cast-iron  boxes,  but  also  for  anneal- 
ing heavy  steel  dies,  hubs,  tool  steel,  etc.  The  slab  which  divides 
the  combustion  chamber  from  the  heating  chamber  is  heavier  than 
in  oven  furnaces,  properly  supported  by  brickwork  to  bear  heavy 
weights,  and  cast-iron  rails  are  placed  over  the  slab  on  which  the 
boxes  are  removed  in  and  out. 

The  burners,  B,  cover  the  whole  length  of  the  heating  space ; 
the  opposite  burners  are  connected  to  one  gas  and  one  air  valve, 


68 


HARDENING,    TEMPERING   AND   ANNEALING. 


which  control  the  supply.  The  door  plug,  P,  is  of  the  exact  size 
and  thickness  of  the  entrance,  so  that  it  can  be  easily  inserted  or 
removed  by  cast-iron  skeleton  door,  D. 

The  advantages  of  gas  blast  case-hardening  furnaces  are  that 
they  do  work  more  quickly  and  thoroughly  than  in  the  best  of 
coal  ovens  in  use,  because  from  the  beginning  of  the  operation  all 


FIG.  37.— CASE-HARDENING  FURNACE. 

the  boxes  inserted — and  all  parts  of  each  box — are  heated  sim- 
tillaneously  and  alike,  and  that  the  heat  can  be  kept  constant  at  the 
maximum  degree  which  the  cast-iron  boxes  will  stand.  These 
advantages  shorten  the  process  materially,  and  when  once  the 
time  required  for  a  given  amount  and  kind  of  work  has  been  as- 
certained, the  same  result  can  be  produced  thereafter,  in  the  same 
time. 


HEATING   STEEL — GAS   BLAST   FURNACES. 


69 


Heating  Machine  for  Hardening  the  Edges  of  Mower  Blades. 
The  machine  shown  in  Fig.  39  is  used  for  hardening  the  edges 
of  mower  blades,  and  will  operate  as  fast  as  the  blades  can  be 
dropped  into  the  jaws  of  the  link  belt  K  at  I.  The  jaws  are  so 
formed  as  to  expose  only  the  edge  of  the  blade  as  far  as  it  is  to  be 
hardened,  to  the  action  of  the  heat,  while  the  body  of  the  blade  is 


FIG.  38. — CASE-HARDENING  FURNACE. 

protected  by  the  shape  of  the  jaws  as  they  close  upon  the  blade 
before  entering  the  heating  chamber. 

The  speed  of  delivery  is  regulated  by  a  countershaft  with 
friction  cone,  placed  above  the  machine  and  connected  with  the 
driving  pull,  H.  The  burners,  B,  emit  a  short  focus  flame  from 
both  sides  and  are  under  the  perfect  control  of  the  gas  valve,  G, 
and  the  air  valve,  A.  The  jaws  of  the  link  belt  open  as  they  pass 
over  the  center  of  the  sprocket  at  I,  where  the  blades  are  inserted, 
closing  just  as  they  enter  the  furnace,  and  the  blades  pass  through 
the  heating  space  at  the  proper  speed,  first  ascertained  by  a  few 


70  HARDENING,    TEMPERING   AND    ANNEALING. 

pilot  blanks  run  through  the  furnace,  and  are  dropped  into  the 
cooling  bath  from  the  mouth,  E,  at  the  exact  heat  required  for 
hardening  the  cutting  edges. 

The  gas  connects  at  union,  G,  and  air,  under  a  pressure  of  at 
least  I  pound  to  the  square  inch,  at  A.  Where  the  machine  is  to 
be  used  on  one  uniform  kind  of  blade,  the  proper  speed  may  be 
experimentally  obtained,  and  the  friction  cone  countershaft  dis- 


FIG.  39. — HEATING   MACHINE   FOR   HARDENING   MOWER   BLADES. 

pensed  with.    Where  the  blades  differ  in  thickness  or  size,  a  fric- 
tion cone  is  indispensable. 

Heating  Machine  for  Hardening  Cones  and  Shells. 

In   Fig.  40  is  shown  a  furnace  that  is  used   for  hardening 

cones,  shells,  pinions  and  similar  small  work,  which  can  be  stuck 

on  the  pins,  which  are  inserted  in  the  links  of  the  endless  chain. 

The  work  passes  through  the  evenly  heated  furnace  at  a  properly 


HEATING  STEEL — GAS   BLAST    FURNACES.  /I 

regulated  speed  and  is  discharged  from  the  mouth,  F,  as  fast  as  it 
is  fed  into  the  bath,  T,  without  needless  exposure  to  the  air.  The 
heat  is  under  absolute  control  and  the  speed  of  the  chain  is  ad- 
justed to  it  so  as  to  impart  the  exact  temperature  to  the  work  re- 
quired for  proper  hardening.  When  constantly  used  for  the  same 
work  the  proper  speed  of  the  chain  is  ascertained  experimentally 
by  turning  the  pull  by  hand  and  then  speeding  the  machine  ac- 


FIG.   40.  —  HEATING   MACHINE   FOR   HARDENING   CONES   AND 


cordingly.     When  used  for  a  variety  of  work  countershaft  with 
friction  cone  pulleys  is  needed. 

Heating  Machine  with  Revolving  Trays. 

The  furnace  shown  in  Fig.  41  is  used  for  tempering  needles, 

small  blades,  springs  and  screws.    Its  action  depends  upon  heated 

air,  with  temperature  so  regulated  that  articles  of  irregular  shape 

can  be  exposed  to  it  long  enough  to  impart  the  correct  color  or 


HARDENING,    TEMPERING    AND    ANNEALING. 


.  41. — HEATING   MACHINE  WITH   REVOLVING  TRAYS, 


HEATING  STEEL GAS   BLAST   FURNACES.  73 

temper  to  the  heavier  section,  without  overheating  the  thinnest 
and  lightest  part  of  the  same  piece.  This  is  accomplished  by 
regulation  of  the  burner,  which  is  usually  divided  into  three  sec- 
tions, each  under  separate  control.  By  these  means  the  injection 
of  the  heat  evenly  throughout  the  furnace  is  easily  secured,  and 
the  overheating  of  either  end  or  the  center  is  prevented.  The 
burners  heat  an  air  chamber  connected  with  the  air  drum  by  the 
pipe  and  valve  A3,  and  heated  air  is  distributed  in  the  heating 
chamber  through  perforations  in  the  top  of  the  air  chamber  under 
light  pressure,  relieved  through  the  vent  cock  at  N.  The  work  is 
placed  in  the  pans,  DD,  which  rotate  at  a  speed  of  twice  or  thrice 
per  minute,  hanging  loosely  from  rods  connected  with  spokes 
around  the  driving  shaft  in  the  center,  which  receives  motion  from 
the  worm  gear,  IH,  connected  with  power.  The  door,  E,  is  closed 
when  furnace  is  charged  with  work,  and  opened  for  its  observation. 
When  open,  the  door  forms  a  shelf  or  rest  for  the  pans.  The 
thermometer  indicates  a  degree  of  temperature  somewhat  different 
from  the  actual  heat  in  the  furnace.  Once  tried  for  a  certain 
temper  of  color,  it  is  a  perfect  guide  for  repeating  the  same  re- 
sult. 

Heating  Machine  for  Small  Parts. 

The  style  of  heating  machine  shown  in  Fig.  42  is  used  for 
heating  large  quantities  of  small  steel  work  of  uniform  size  and 
weight,  evenly  and  uniformly,  to  any  required  degree  for  hard- 
ening, or  for  annealing  the  same,  automatically.  The  work  Is 
placed  on  the  cast-iron  link  belt,  Ci,  which  revolves  entirely 
within  the  heating  chamber,  N,  except  where  momentarily  exposed 
at  entrance,  M,  to  receive  the  work.  The  burners,  B,  penetrate 
from  each  side  of  the  furnace  above  the  link  belt,  and  are  perfectly 
controlled  by  the  gas  valve,  G,  and  the  air  valve,  A. 

The  belt  is  supported  by  sprockets  in  the  heating  chamber, 
whose  shafts  revolve  on  the  rolls,  D.  The  belt  is  moved  at  re- 
quired speed  by  means  of  a  friction  cone  which  is  placed  above  the 
machine  and  connects  with  the  driving  sprockets,  F,  by  the  chains, 
HH. 

The  weight  and  size  of  the  work,  and  the  degree  of  heat  which 
it  requires,  determine  the  speed  at  which  the  belt  is  moved, 
and  consequently  the  output.  The  temperature  of  the  heating 
chamber  and  the  speed  of  the  belt  being  under  perfect  control, 
the  output  is  only  limited  by  the  time  it  takes  to  heat  the  work  to 
the  exact  degree  required. 


74 


HARDENING,    TEMPERING   AND   ANNEALING. 


HEATING   STEEL GAS   BLAST    FURNACES. 


75 


The  cooling  part  is  not  a  part  of  the  machine,  but  is  shown 
merely  to  illustrate  the  whole  operation.  A  proper  cooling  bath 
is  important.  It  should  be  of  ample  size,  and  so  arranged  as  to 
promptly  cool  the  work  without  varying  materially  the  tempera- 
ture of  the  oil.  Gas  connection  is  made  to  the  union,  G,  and  an 
air  blast  from  a  positive  pressure  blower  connects  at  A. 

Barrel  Healing  Machine  for  Hardening  Balls,  Saw  Teeth,  Screws, 

Etc. 
A  type  of  machine  designed  for  hardening  quantities  of  bicycle 


FIG.    43. — AUTOMATIC    BARREL    HEATING    AND   HARDENING   MACHINE. 

balls,  but  which  has  since  been  used  for  hardening  detachable 
saw  teeth,  pens,  nuts,  bolts,  screws,  and  other  work  not  exceed- 
ing two  and  one-half  inches  in  any  dimension,  is  shown  in  Figs. 
43  and  44. 

Steel  work  of  any  shape  is  evenly  and  thoroughly  heated  to 


76  HARDENING,    TEMPERING   AND    ANNEALING. 

the  exact  degree  required,  regardless  of  its  shape,  the  thinnest  and 
thickest  parts  being  discharged  at  exactly  the  same  temperature. 

The  machine  is  capable  of  heating  from  1,500  to  2,000  pounds 
of  steel  work  per  day,  the  rate  of  delivery  depending  upon  weight 
and  shape  of  the  piece. 

The  cooling  bath  marked  X  in  the  cut  is  merely  a  suggestion 
and  its  size  depends  upon  the  work  to  be  done,  as  well  as  upon 
the  available  water  supply  for  cooling.  Its  size  and  construction 


FIG.    44. — LONGITUDINAL  SECTION   THROUGH   CENTER   OP   BARREL 
HEATING   MACHINE. 

also  depend  upon  the  temperature  of  the  water  to  be  used,  and 
will  vary  under  different  circumstances. 

Different  methods  are  employed  to  cool  oil  baths.  One  is  to 
draw  the  hot  oil  from  the  top,  running  it  through  pipes  immersed 
in  cold  water,  and  pumping  it  back  to  the  bottom  of  the  tank 
cooled.  Another  is  as  illustrated.  The  tank  holding  the  oil  is 
shallow  and  water  jacketed,  the  water  being  circulated  at  the  rate 
required  to  keep  the  bath  at  proper  temperature,  determined  by 
reference  to  a  thermometer. 

Where  the  water    supply  itself  is  not  sufficiently  cool,  the  bath 


HEATING   STEEL — GAS   BLAST   FURNACES.  77 

may  require  cooling  by  ice,  or  the  operation  of  the  furnace  may 
have  to  be  limited  to  the  capacity  of  the  bath. 

In  several  instances  a  machine  of  the  type  has  heated  work 
faster  than  it  could  be  cooled,  and  the  possible  output  therefore 
greatly  depends  upon  the  bath. 

Construction  and  Operation. 

The  cylindrical  body  of  the  machine  heavily  lined  with  fire- 
brick incloses  a  solid  cast-iron  cylinder  with  a  spiral  way,  2% 
inches  to  3  inches  wide.  The  shaft  of  this  "spiral  way  cylinder" 
is  a  heavy  wrought-iron  pipe  containing  the  wrought-iron  spiral, 
E.  This  hollow  shaft  and  the  cast-iron  spiral  cylinder  revolve 
together.  The  heat  is  generated  over  the  drum  and  is  evenly  dis- 
tributed from  both  sides  of  the  burners,  R.  The  products  of  com- 
bustion are  allowed  to  enter  the  spiral  drum,  thus  excluding 
atmospheric  air  from  it  to  prevent  oxidation,  and  find  their  vent 
through  the  bottom  of  the  furnace  by  being  forced  through  the 
charge,  I. 

The  work  being  placed  in  the  hopper,  B,  which  is  kept  filled  to 
the  level  of  the  entrance,  the  scoop,  C,  revolving  with  the  cylinder, 
fills  itself  with  work  as  it  is  rotated  downward,  and  empties  its 
contents  into  the  stationary  funnel,  D,  when  it  rotates  to  a  position 
above  it.  From  this  feeding  funnel,  D,  the  work  drops  into  the 
spiral  way,  E,  and  is  propelled  to  the  opposite  end  of  the  inner 
spiral,  where  it  drops  into  the  outer  cast-iron  spiral  way,  H,  in 
which  it  is  propelled  in  the  opposite  direction  and  drops  from  the 
cylinder,  I,  to  the  chute,  K,  into  the  cooling  bath,  L. 

The  stationary  feeding  funnel,  D,  with  the  scoop,  C,  the  in- 
terior spiral,  E,  and  the  cast-iron  spiral  drum,  IH,  revolve  to- 
gether by  action  of  the  worm  gear,  P  O.  The  number  of  revolu- 
tions required  to  discharge  the  work  at  the  proper  heat  are  experi- 
mentally ascertained,  and  the  rate  of  discharge  being  once  estab- 
lished, the  machine  will  turn  out  a  perfectly  uniform  product. 

The  speed  is  regulated  by  a  "friction  cone"  countershaft  placed 
overhead,  from  which  the  power  is  transmitted  to  the  pulleys,  Q. 

The  furnace  is  lighted  by  withdrawing  the  plug,  N,  and  turn- 
ing on  the  air  full,  inserting  a  torch,  and  then  turning  on  just 
sufficient  gas,  so  that  the  burners  emit  a  perfectly  blue  flame. 
The  gas  and  air  supply  valves,  A  and  G,  permit  the  heat  to  be 
regulated  to  exact  requirements.  The  temperature  of  the  drum 
can  be  observed  by  the  removal  of  the  lighting  plug,  N,  and  by 


78  HARDENING,    TEMPERING   AND    ANNEALING. 

means  of  the  friction  cone  the  time  required  for  heating  and  de- 
livery can  be  regulated  with  precision. 

It  will  usually  require  from  45  minutes  to  one  hour  to  heat  the 
spiral  ways  for  hardening.  At  the  expiration  of  that  time  the 
machine  will  turn  out  the  work  at  a  regular  rate.  Where  thin 
and  thick  work  are  put  through  the  machine  together,  the  time  of 
delivery  will  be  determined  by  the  heaviest  article  put  through, 
but  the  lightest  or  thinnest  will  not  be  overheated  unless  the  tem- 
perature is  allowed  to  increase  beyond  the  highest  degree  required 
by  hardening. 

The  main  body  of  the  machine  is  a  solid  fireclay  cylinder  in- 
closed by  a  heavy  sheet-iron  casing.  All  bearings  are  ball  or 
roller  bearings,  needing  but  little  lubrication.  Both  heads  of  the 
machine  can  be  removed  for  the  inserting  of  a  new  cylinder  when 
required,  the  body  of  the  furnace  resting  independently  upon  the 
table,  thus  remaining  in  position  if  heads  are  detached. 

Heating  Machine  for  Tempering  and  Coloring  Steel. 

A  machine  for  tempering  and  coloring  steel  work  in  quantities 
with  perfect  uniformity  is  shown  in  Fig.  45.  The  cut  represents 
an  improved  type  of  machine  which  has  been  in  satisfactory  opera- 
tion for  several  years,  for  tempering  and  coloring  pens,  bicycle 
chain  link  blocks,  penholders,  saw  teeth,  screws,  buttons,  and 
other  similar  work  not  over  two  inches  in  any  dimension. 

The  operation  is  performed  by  subjecting  the  work  to  the 
action  of  sand  or  ground  flint  heated  to  the  proper  degree  re- 
quired for  any  grade  of  temper,  and  a  bright,  clean  and  perfectly 
uniform  temper  color  is  obtained  when  the  work  has  been  properly 
prepared  for  coloring  by  thorough  cleansing. 

The  capacity  of  the  machine  depends  upon  the  size  and  weight 
of  the  articles,  but  as  a  criterion  for  its  efficiency  we  can  say  that 
we  have  witnessed  bicycle  chain  blocks  and  insertable  saw  teeth 
being  put  through  at  the  rate  of  150  pounds  per  hour. 

The  work  is  placed  in  the  hopper,  X,  containing  a  small  scoop, 
which  at  every  revolution  deposits  a  measured  quantity  into  a  fun- 
nel leading  into  the  heating  drum.  This  drum,  contained  in  the 
main  body  of  the  machine,  is  provided  with  a  spiral  way  which 
gradually  propels  the  work  to  discharge  Z. 

The  spiral  partitions  are  inclosed  by  a  perforated  cylinder, 
through  which  sand  or  flint  heated  to  the  proper  temperature  to 


HEATING   STEEL GAS    BLAST   FURNACES. 


79 


obtain  a  desired  temper  or  color  is  constantly  sifted  upon  the 
work. 

Provisions  are  made  to  keep  a  sufficient  quantity  of  sand  stored 


FIG.  45. — HEATING   MACHINE   FOR  TEMPERING   AND   COLORING. 

above  the  work,  so  as  to  secure  its  even  distribution  into  all  the 
spiral  divisions  of  the  drum,  thus  effecting  its  uniform  action  upon 
the  work. 

The  outer  casing  of  the  drum  is  subjected  to  an  evenly  distri- 


8o 


HARDENING,    TEMPERING    AND    ANNEALING. 


buted  heat,  controlled  by  proper  adjustment  of  the  gas  valve,  Gr 
and  the  air  valve,  B. 

The  speed  at  which  the  work  passes  through  the  spiral  drum  Is 
regulated  by  a  friction  cone  placed  above  the  machine,  and  the 
temperature  by  reference  to  the  thermometer,  I. 

By  noting  the  temperature  at  which  different  colors  are  ob- 


FIG.  46. — CIRCULAR   ANNEALING    AND   HARDENING    FURNACE. 


HEATING   STEEL GAS   BLAST   FURNACES.  8 1 

tained  by  a  given  rate  of  delivery,  the  exact  conditions  of  heat 
and  speed  under  which  a  variation  of  color  or  temper  is  obtained 
can  be  readily  observed  and  the  perfect  uniformity  of  the  output 
assured. 

Circular  Annealing  and  Hardening  Furnace. 

The  furnace  shown  in  Fig.  46  is  used  for  heating  large  rims, 
rings,  discs,  dies  and  other  circular  steel  blocks  which  do  not  ex- 
ceed 30  inches  in  diameter  and  10  inches  in  thickness. 

The  illustration  shows  a  circular  block,  K,  resting  upon  the  fire- 
brick supports,  H,  so  placed  that  they  do  not  in  any  way  obstruct 
the  flames  emitted  from  the  four  burners,  B.  The  direction  of 
the  flame  is  tangential  at  the  proper  angle,  to  secure  a  rotary  or 
whirling  motion  of  the  flame,  and  the  even  distribution  of  the  heat, 
-effecting  the  perfectly  even  heating  of  the  work.  This  should  be 
placed  centrally,  i.  e.,  equidistant  from  the  inner  walls  of  the 
•cylindrical  casing. 

The  cover,  D,  is  attached  to  the  cover  lift,  and  held  by  the 
adjustable  chains,  EE.  It  is  lifted  by  a  toggle  joint  by  pulling  the 
lever  handle  inserted  in  the  socket,  L,  forward,  and  easily  swings 
to  either  side.  To  replace  the  firebrick  cover,  the  clasp,  M,  on 
the  sheet  iron  belt  which  tightly  incloses  it  is  unscrewed,  and  a 
new  brick  lining  inserted.  The  valve,  G,  admits  gas  and  connects 
with  the  gas  supply.  A  connects  with  air  supply. 

Oil  Tempering  Furnaces. 

Furnaces  of  the  type  shown  in  Figs.  47  and  48  are  used  for 
tempering  steel  work  in  oil  or  tallow,  and  have  the  advantage 
over  similar  apparatus  heated  by  coal  that  the  heat  is  evenly  dis- 
tributed and  penetrates  the  bath  from  all  sides,  that  the  temperature 
is  under  perfect  control,  that  no  flame  can  escape  from  the  com- 
bustion chamber  to  ignite  the  oil  or  fumes  arising  from  it,  and 
that  the  temperature  of  the  oil  can  be  raised  to  an  exceptionally 
high  degree  without  risk  of  flashing.  They  are  made  in  shapes 
and  sizes  to  suit,  round,  square  or  oblong. 

Furnace,  Fig.  47,  has  the  burners,  B,  arranged  in-two  separate 
sections  of  four,  two  on  each  side,  each  section  being  under 
separate  control  of  the  gas  and  air  valves  below  the  distributing 
pipes,  D  and  E,  respectively. 

To  heat  up  the  bath,  both  sets  of  burners  are  turned  on,  and 
when  the  desired  temperature  is  reached,  as  indicated  by  the  ther- 


82 


HARDENING,    TEMPERING   AND    ANNEALING. 


mometer,  L,  one  set  of  four  burners  can  instantly  be  put  out  of 
use,  so  as  to  prevent  the  too  rapid  increase  of  the  heat  to  the  flash 
point. 

The  work  is  placed  in  the  basket,  K,  which  may  be  filled  to  the 
top.     The  immersion  of  the  work  in  the  bath  quickly  reduces  its 


,  FIG.  47.— OIL   TEMPERING   FURNACE. 

temperature,  and  the  work  remains  in  the  bath  until  the  ther- 
mometer shows  that  the  heat  of  the  bath  is  restored  in  the  proper 
degree.  The  best  oil  to  be  used  is  "Black  Tempering  Oil,"  gen- 
erally supplied  by  the  agencies  of  the  Standard  Oil  Company, 


HEATING   STEEL GAS   BLAST   FURNACES.  83 

which  can  be  raised  to  a  temperature  of  600  deg.  F.,  and  will  tem- 
per steel  from  straw  color  to  a  light  blue.  The  basket,  K,  is  18 
inches  long,  10  inches  wide  and  8  inches  deep. 

Oil  tempering  furnace,  Fig.  48,  in  its  construction  is  similar 


FIG.  48. — CIRCULAR   OIL  TEMPERING  FURNACE. 


to  that  of  a  soft  metal  furnace.  The  pot  is  iol/2  inches  in  diam- 
eter, 10  inches  deep,  and  the  temperature  is  regulated  by  reference 
to  the  thermometer,  T,  held  in  place  by  the  clamp,  K.  The  bulb 
of  the  thermometer  extends  below  the  middle  of  the  bath,  and  the 
burners  are  arranged  to  distribute  the  heat  with  perfect  evenness 
around  the  pot. 

For  small  work  a  wire  basket  is  used  to  contain  the  articles  to 
be  treated,  while  larger  work  is  suspended  in  the  bath  in  any  con- 
venient way.  The  temperature  being  under  the  perfect  control 
of  the  gas  and  air  valves,  G  and  A,  the  bath  is  heated  until  the 
thermometer  shows  the  proper  heat.  When  work  is  submerged 
in  the  bath  it  cools  down,  and  the  work  remains  there  until  the 


«4 


HARDENING,    TEMPERING   AND   ANNEALING. 


HEATING   STEEL GAS   BLAST   FURNACES.  85 

temperature  rises  again  to  the  original  degree,  when  the  work 
is  removed. 

Heating  Machine  for  Hardening  Chain. 

This  machine  shown  in  Fig.  49  is  one  of  many  heating  devices 
built  for  special  purposes. 

The  idea  successfully  accomplished  in  this  machine  is  to  harden 
chains  made  from  sheet  steel,  which  passes  from  reel  Ri  first 
through  the  heating  space  into  the  cooling  bath  and  is  received  on 
reel  R2  perfectly  and  uniformly  hardened. 

By  the  accurate  adjustment  of  burners  and  speed  of  travel  a 
perfect  uniformity  in  hardness  of  all  the  links  is  secured,  the 
cooling  bath  is  kept  at  a  uniform  temperature  by  proper  circula- 
tion of  the  water  or  oil,  which  is  drawn  off  the  top,  and  after  cool- 
ing is  pumped  back  into  the  bath  at  the  bottom.  After  the  chain 
is  hardened  and  wound  upon  the  reel  the  whole  reel  is  inserted 
in  an  oil  tempering  furnace  to  be  drawn  to  the  exact  temper 
required. 

Cylindrical  Case-Hardening  Furnace. 

Furnaces  of  the  type  shown  in  Fig.  50  are  used  for  case-hard- 
ening car  axles  of  about  6  inches  in  diameter  and  not  exceeding  8 
feet  in  length. 

The  axle  is  inserted  in  the  wrought-iron  tube,  R,  having  an 
interior  diameter  of  10  inches.  The  axle  is  placed  in  the  exact 
center  of  the  retort  and  the  carbon  packed  tightly  around  it,  after 
covering  such  parts  as  are  not  to  be  case-hardened  with  fire-clay 
or  some  other  non-carbonaceous  material.  The  retort  being 
packed  it  is  let  down  into  the  furnace  from  a  suitable  crane  over- 
head, and  the  cover,  K,  put  in  position  as  shown,  when  the  furnace 
is  ready  for  operation. 

The  distribution  of  the  heat  evenly  from  the  bottom  to  the  top 
of  the  retort  is  effected  by  two  independently  controlled  sets  of 
burners ;  the  lower  set  by  the  valves  G2  and  A2,  and  the  upper  set 
by  the  valves  63  and  A3,  while  the  common  supply  valves  are 
Gi  and  Ai.  G  stands  in  each  case  for  gas  and  A  for  air. 

The  proper  adjustment  having  been  made  on  the  lower  and 
upper  sets  of  the  burners  so  as  to  secure  an  approximately  correct 
distribution  of  the  heat,  the  main  gas  and  air  valves  are  alone 
utilized  to  control  the  temperature,  and  the  distribution  of  the 
heat  properly  over  the  whole  length  is  then  effected  by  the  two 
vents,  one  in  the  bottom  indicated  by  M2,  ami  one  on  top  in  the 


86 


HARDENING,    TEMPERING   AND   ANNEALING. 


FIG.  50. — CYLINDRICAL  CASE-HARDENING  FURNACE  FOR   CASE 
HARDENING  CAR  AXLES. 


HEATING  STEEL — GAS   BLAST   FURNACES.  O/ 

center  of  the  cover,  K.  The  top  vent  being  closed  entirely,  the 
heat  is  driven  downward  and  the  products  of  combustion  escape 
through  the  vent,  N2.  If  N2  is  closed  and  cover  vent  wide  open, 
the  heat  is  forced  upward  too  rapidly,  but  by  partly  closing  both 
vents,  as  much  as  will  be  found  necessary  from  observation,  a 


FIG.   51. — CYLINDRICAL    CASE-HARDENING    FURNACE. 


88 


HARDENING,    TEMPERING    AND    ANNEALING. 


perfectly  uniform  distribution  of  the  heat  is  effected  without  a 
very  close  adjustment  of  the  relative  strength  of  the  upper  and 
lower  burner  tiers. 

The  regulation  of  the  distribution  by  the  vent  holes  is  espe- 
cially important  when  the  temperature  is  to  be  raised  quickly 
and  the  burners  turned  on  as  full  as  possible  in  both  tiers. 

Each  row  of  burners  has  three  burner  tips,  F,  as  shown,  which 


FIG.  52. — SOFT   METAL  FURNACE   FOR   LEAD   HARDENING. 

enter  the  cylinders  from  four  sides  at  the  proper  angle  to  secure 
a  rotary  motion  of  the  flame  around  the  retort  without  impinging 
upon  it.  The  body  of  the  furnace  contains  three  observation  holes 
closed  by  the  plugs,  Li,  L2,  and  L3.  The  lighting  hole  is  not 
visible  in  cut  but  is  indicated  in  the  rear  of  the  furnace  by  N2  and 
closed  by  the  plug  Ni. 

Lead  Hardening  Furnace. 
The  style  of  furnace  shown  in  Fig.  52  is  used  for  heating  lead 


HEATING  STEEL GAS   BLAST    FURNACES.  89 

in  black  lead  crucibles  of  any  regular  size  for  hardening  steel 
work. 

Any  black  lead  crucible  used  for  lead  hardening  must  be  regu- 
larly emptied  after  each  operation.  If  the  lead  is  allowed  to  cool 
and  solidify,  the  crucible  will  crack  when  heated  up  again. 


9O  HARDENING,    TEMPERING   AND   ANNEALING. 

Melting  Pots. 

Figs.  53  and  54  show  charts  of  pots  used  for  melting  soft 
metals  and  for  heating  cyanide  or  lead  for  hardening,  and  oil  or 
tallow  for  tempering. 


HEATING  STEEL GAS   BLAST    FURNACES.  QI 

Cyanide  Hardening  Furnaces. 

The  furnace  shown  in  Fig.  55  is  of  a  type  used  for  heating 
-steel  work  in  cyanide  of  potassium  for  hardening ;  they  are  used 
by  the  leading  bank  note  engravers  in  the  United  States  for  hard- 
ening transfer  rolls  and  engraved  plates,  and  by  manufacturers 


FIG.  55. — CYANIDE  HARDENING  FURNACE  FOR  CUTTERS, 
DIES,    ROLLS,   ETC. 


92  HARDENING,    TEMPERING   AND    ANNEALING. 

for  hardening  cutters,  dies,  springs,  and  other  steel  work  requiring 
a  hardened  surface.  Their  general  features  are  also  utilized  in 
apparatus  for  heating  chemical  solution  where  the  escape  of 


HEATING   STEEL GAS   BLAST  FURNACES.  93 

poisonous  fumes  from  the  pot  or  caldron  into  the  room  must  be 
prevented.  It  contains  a  cast-iron  or  steel  pot  suspended  by  a 
flange  with  raised  edge  in  the  center  of  the  heating  chamber. 
The  two  opposite  burners,  BB,  inject  the  flames  into  the  space 
between  the  pot  and  surrounding  firebrick  lining,  and  heat  the 
pot  evenly  without  coming  in  direct  contact  with  it.  The  two 
lighting  holes  in  front  are  closed  after  the  furnace  is  put  in  op- 
eration, and  the  products  of  combustion  find  their  outlet  in  the  pipe, 
E,  which  extends  upward  in  the  rear  and  enters  the  elbow  on  the 
sheet-iron  pipe,  S,  passing  the  draft  hole  near  the  top  of  the  hood, 
H.  The  heat  from  the  combustion  chamber  is  thus  injected  into 
the  draft  pipe,  S,  and  a  positive  draft  is  created  which  carries  off 
the  fumes  as  they  rise  from  the  pot.  Thus  the  poisonous  fumes 
are  carried  off  into  the  chimney,  and  with  ordinary  care  none 
escapes  into  the  room.  Gas  and  air  are  indicated  at  G  and  A. 

Regular  Sizes  of  Muffles. 

The  annexed  chart,  Fig.  56,  shows  the  regular  sizes  of  muffles 
which  are  on  the  market.  The  number  of  the  muffle  corresponds 
to  the  number  of  the  furnace,  so  that  orders  .for  the  muffles  can 
be  given  by  the  furnace  number,  or  a  furnace  ordered  by  the  num- 
ber of  the  muffle. 

The  dimensions  of  muffles  are  their  interior  measurement. 

Muffle  Furnace. 

The  muffle  furnace  shown  in  Fig.  57  is  typical  of  large  sizes 
for  heavy  kinds  of  work  requiring  high  heat.  It  is  entirely  en- 
cased in  cast-iron  framework  firmly  bolted  together,  with  heavy 
linings  and  carefully  trimmed  and  fitted  fireclay  sections.  The 
casing  is  filled  in  above  and  around  the  arch  with  non-conducting 
material  to  lessen  radiation,  and  the  muffle  bottom  is  protected 
by  extra  supports,  as  in  oven  furnaces,  to  prevent  sagging  under 
weight. 

Tough  Steel  and  Hard  Steel — The  Difference. 
Although  few  mechanics  seem  to  be  aware  of  it,  there  is  con- 
siderable difference  between  steel  which  is  hard  and  steel  which  is 
both  hard  and  tough,  i.  e.,  when  a  tool  has  been  hardened  and 
tempered  to  the  degree  thought  best  for  the  work  which  it  is  to 
perform  and  the  edge  does  not  stand  up,  but,  instead,  crumbles 
away,  the  steel  is  hard  but  is  not  tough  and  was  heated  wrongly  in 


94 


HARDENING,    TEMPERING   AND   ANNEALING. 


hardening,  or  was  not  quenched  right.  On  the  contrary,  when  a 
tool  has  been  heated  properly  and  hardened  and  tempered  as  it 
should  be,  it  can  be  very  hard  and  the  edge  will  hold  because  for 
given  degrees  of  hardness  the  same  degree  of  toughness  has  been 
imparted  during  the  heating  and  hardening  processes. 


N 


FIG.  57. — MUFFLB  FURNACE. 


CHAPTER   IV. 

THE    HARDENING    OF    STEEL HARDENING    IN    WATER,    BRINE,    OIL, 

AND    SOLUTIONS SPECIAL    PROCESSES    FOR    SPECIAL    STEEL. 

Judgment  and  Carefulness  in  Hardening. 

As  a  great  deal  depends  on  the  judgment  and  carefulness  of 
the  man  who  does  the  hardening  in  a  shop,  in  all  large  manufac- 
turing establishments  the  job  of  doing  all  the  hardening  should 
be  given  to  one  man.  On  this  man's  efficiency  and  judgment  will 
depend  the  increasing  or  the  reducing  of  the  cost  account,  as  one 
piece  of  steel  which  has  been  hardened  properly  will  accomplish 
many  times  as  much  as  a  piece  which  has  been  hardened  imper- 
fectly. The  manner  in  which  the  operator  puts  the  steel  into  the 
quenching  liquid  will  be  responsible  more  than  anything  else,  for 
having  the  pieces  come  out  hard  and  free  from  cracks  or  deformi- 
ties. Work  with  deep  recesses  will  often  have  to  go  into  the  water 
with  the  recessed  part  first,  or  vise  versa,  according  to  the  shape 
and  location  of  the  same. 

When  hardening  large  pieces  which  are  worked  out  in  the 
center,  a  stream  of  water  striking  against  them  is  often  abso- 
lutely necessary.  There  are  some  grades  of  steel  which  will  give 
the  best  results  if  they  are  removed  from  the  water  as  soon  as  the 
vibration  has  ceased  and  laid  aside  until  cold.  Experience,  skill, 
and  good  sound  judgment  are  necessary  to  do  good  hardening. 

Successful  Hardening. 

In  almost  every  establishment  where  any  large  amount  of  steel 
is  hardened,  some  one  man  will  be  found  who  is  considered  an 
expert  in  the  art.  When  such  men  really  possess  the  required 
judgment  and  skill  they  are  careful  in  the  heating  and  quenching, 
and  good  results  are  attained.  Very  often,  however,  the  man  who 
is  considered  an  authority  on  the  subject,  possesses  very  little  real 
knowledge,  but  instead,  through  pure  "gall"  and  "nerve,"  takes 
chances  and  either  comes  out  on  top  or  manages  to  cover  up  his 
mistakes.  Beware  of  such  men ;  they  are  responsible  for  more 
bad  work  in  the  shop  than  any  others. 

First  and  foremost,  the  effect  of  annealing  on  steel  which  is 


96  HARDENING,    TEMPERING   AND    ANNEALING. 

desired  to  be  afterward  hardened  must  be  understood  and  appre- 
ciated. First,  the  annealing  process  softens  and  allows  the  steel 
to  be  worked  into  shape  with  ease.  Second,  it  removes  all  strains 
sustained  in  the  manufacture,  such  as  rolling,  hammering  and 
forging.  Thus  experience  teaches  that  it  is  necessary  to  anneal 
any  odd  shaped  piece  after  all  the  surface  scale  has  been  removed 
and  the  piece  roughed  down. 

Different  Quenching  Baths — Their  Effect  on  Steel. 

As,  next  to  proper  heating,  more  depends  upon  the  quenching 

than  anything  else,  it  follows  that  the  effects  of  the  use  of  the 

various  kinds  of  baths  are  required  to  be  understood.     The  most 

generally  used  bath  is  usually  cold  water,  though  not  infrequently 


iBP^^i  xffi|fep 


FIG.  58. — SCREW   MACHINE   SPRING   THREADING   DIES. 

•salt  is  added  or  a  strong  brine  is  used.  The  following  will  be 
found  to  answer  well  for  the  work  mentioned :  For  very  thin  and 
delicate  parts,  an  oil  bath  should  be  used  for  quenching.  For 
small  parts  which  are  required  to  be  very  hard,  a  solution  composed 
of  about  a  pound  of  citric  acid  crystals  dissolved  in  a  gallon  of 
water  will  do.  For  hardening  springs,  sperm  oil ;  and  for  cutting 
tools,  raw  linseed  oil  will  prove  excellent. 

Boiled  water  has  often  proved  the  only  bath  to  give  good 
results  in  a  large  variety  of  work,  the  parts  requiring  hardening 
being  heated  in  a  closed  box  or  tube  to  a  low  red  heat  and  then 
quenched.  Sometimes  the  water  should  be  boiling,  at  others  quite 
hot,  and  then  again  lukewarm.  Experience  will  teach  the  operator 


THE    HARDENING    OF    STEEL. 


97 


which  is  the  best  for  special  work.  If  a  cutting  tool  such  as  a 
hollow  mill,  a  spring  threading  die  or  a  similar  tool  is  to  be  hard- 
ened in  a  bath  of  this  sort  dip  it  with  the  hole  up  or  the  steam  will 
prevent  the  liquid  from  entering  the  hole  and  leave  the  walls 
soft.  A  tendency  to  crack  will  also  prevail  if  this  is  not  done. 
The  generation  of  steam  must  be  considered  when  hardening 
work  with  holes  or  depressions  in  it,  and  attention  must  be  paid 
to  the  dipping  of  the  part  so  as  to  prevent  the  steam  from  crowd- 
ing the  water  away.  Clean  water  steams  rapidly,  while  brine 
and  the  different  acid  solutions  do  not. 

General  Rules  and  Directions  for  the  Hardening  of  Steel. 

The  effect  of  heat  on  steel  is  to  expand  it,  even  or  uneven 
expansion  depending  upon  the  care  and  throughness  of  the  heat- 
ing operation.  Thus  if  one  part  of  a  piece  is  heated  quicker  or 
higher  than  another  the  expansion  is  uneven,  and  the  shape  of  the 
part  changes  to  accommodate  the  local  expansion.  The  conse- 
quence is  that  distortion  takes  place  and  remains  permanent. 
In  machine  parts  which  have  been  finished  and  fitted  or  in  any 
part  which  it  is  not  practicable  to  grind  afterward,  the  distor- 
tion often  prevents  the  use  of  the  piece,  especially  is  this  so  in 
tools. 

Distortion  Through  Uneven  Heating. 

We  will  suppose,  for  instance,  that  a  part  with  a  thin  side  or 
edge  such  as  the  cutter  blade  of  the  thread  tool  shown  in  Fig. 
59,  is  to  be  hardened.  To  do  this  successfully  the  thin  parts 
must  be  handled  or  manipulated  in  the  fire  so  that  the  frail  side 


FIG.  59. — PATENT   THREAD   TOOI,   AND    PARTS. 


98  HARDENING,,    TEMPERING   AND    ANNEALING. 

will  not  reach  the  hardening  heat  before  the  rest  of  the  body  of 
the  piece,  or  it  will  become  warped  or  distorted,  this  coming 
about,  not  through  the  difference  of  temperature  of  the  various 
parts  as  some  imagine,  but,  instead,  through  the  more  solid  parts 
being  too  strong  to  permit  expansion,  and  when  expansion  is  at 
last  accommodated  it  has  been  at  the  expense  of  the  frailer  part 
of  the  metal.  From  this  it  must  not  be  inferred  that  the  part 
having  the  smallest  sectional  area  is  the  weaker  while  being 
heated,  but  instead  that  it  is  as  strong  as  the  rest  except  when 
at  the  same  temperature.  The  following  extracts  from  an  article 
by  the  late  Joshua  Rose,  M.E.,  in  an  early  number  of  the 
Scientific  American  Supplement,  explains  this  in  a  manner  which 
leaves  nothing  to  be  desired : 

"For  example,  suppose  we  have  an  eccentric  ring,  say  y2  inch 


FIG.    60.—  SPECIAI,  ROUGHING  TURRET  REAMER. 

thicker  on  one  side  than  the  other,  and  heat  it  midway  between 
the  thick  and  thin  sides  to  a  cherry  red ;  while  those  sides  are 
barely  red-hot,  the  part  heated  to  cherry  red  will  be  the  weakest, 
and  will  give  way  most  to  accommodate  the  expansion,  because  the 
strength  due  to  its  sectional  area  has  been  more  than  compen- 
sated for  by  the  reduction  of  strength  due  to  its  increased  tem- 
perature. The  necessity  of  heating  an  article  according  to  its 
shape  then  becomes  apparent,  and  it  follows  that  the  aim  should 
be  to  heat  the  article  evenly  all  over,  taking  care  specially  that 
the  thin  parts  shall  not  get  hot  first.  ...  If  the  article  is 
large  enough,  the  thin  part  may  be  covered,  or  partially  so,  dur- 
ing the  first  of  the  heating  by  wet  ashes.  If,  however,  the  article 
is  of  equal  sectional  area  all  over,  it  is  necessary  to  so  turn  it  in 
the  fire  as  to  heat  it  uniformly  all  over ;  and  in  either  case  care 


THE    HARDENING   OF    STEEL.  99 

should  be  taken  not  to  heat  the  steel  too  quickly,  unless,  indeed, 
it  is  desirable  to  leave  the  middle  somewhat  softer  than  the  out- 
side, so  as  to  have  the  outside  fully  hardened  and  the  inside  some- 
what soft,  which  will  leave  the  steel  stronger  than  if  hardened 
equally  all  through.  Sometimes  the  outside  of  an  article  is  heated 
more  than  the  inside,  so  as  to  modify  the  tendency  to  crack  from 
the  contraction  during  the  quenching,  for  to  what  degree  the 
article  expands  during  the  heating,  it  must  contract  during  the 


FIG.  6l. — TURRET  TAP. 

cooling.  Whether  the  heating  be  done  in  the  open  fire  or  in  a 
heating  mixture,  it  must  be  done  uniformly,  so  that  it  may  be 
often  necessary  to  hold  the  article  for  a  time  with  the  thick  part 
only  in  the  melted  lead  or  other  heating  material ;  but  in  this 
case  it  must  not  be  held  quite  still,  but  raised  and  lowered  gradu- 
ally and  continuously  to  insure  even  heating. 

The  Hardening  Fire  and  the  Heat. 

"The  size  of  an  article  will  often  be  an  important  element 
for  consideration  in  heating  it,  because,  by  heating  steel  in  the 
open  fire,  it  becomes  decarbonized ;  and  it  follows  that  the  smaller 
the  article  in  sectional  area  the  more  rapidly  this  decarbonization 
takes  place.  In  large  bodies  of  metal,  the  decarbonization  due 
to  a  single  heating  is  not  sufficient  to  have  much  practical  sig- 
nificance ;  but  if  the  tool  requires  frequent  renewal  by  forging, 
the  constant  reheating  will  seriously  impair  its  value ;  and  in 
any  event  it  is  an  advantage  to  maintain  the  quality  of  the  steel 
at  its  maximum.  To  prevent  decarbonization  for  ordinary  work 
charcoal  instead  of  coal  is  sometimes  used ;  and  where  hardening 
is  not  done  continuously  it  is  a  good  practice,  because  a  few  pieces 


IOO  HARDENING,    TEMPERING   AND   ANNEALING. 

of  charcoal  can  be  thrown  upon  the  fire  and  be  ready  for  use  on 
a  few  minutes'  notice.  Charcoal  should  be  used  for  the  heating 
for  the  forging  as  well  as  for  that  for  the  hardening.  Green 
coal  should  never  be  used  for  heating  the  steel  for  the  hardening, 
even  if  it  is  for  the  forging  process ;  because,  while  the  steel  is 
being  well  forged,  its  quality  is  maintained,  but  afterward  the 
deterioration  due  to  heating  is  much  more  rapid.  A  coke  suitable 
for  hardening  should  be  made  and  always  kept  on  hand.  To 
obtain  such  a  coke  make  a  large  fire  of  small  soft  coal  well  wetted 
and  banked  up  upon  the  fire ;  and  with  a  round  bar  make  holes  for 
the  blast  to  come  through.  When  the  gas  is  out  of  the  interior 
coal,  and  the  outside  is  well  caked,  it  may  be  broken  up  with  a 
bar,  so  that  the  gas  may  be  burnt  out  of  the  outside,  and  then 
the  blast  may  be  stopped  and  the  coke  placed  ready  for  use  at  a 
moment's  notice.  Good  blacksmiths  always  keep  a  store  of  this 
coke  for  use  in  making  welding  heats  as  well  as  for  hardening 
processes.  .  .  .  If  an  article  has  a  very  weak  part,  it  is  neces- 
sary to  avoid  resting  that  part  upon  the  coal  or  charcoal  of  the 
fire ;  otherwise  the  weight  may  bend  it,  and  in  heating  long  slen- 
der pieces  they  should  bed  evenly  in  the  fire  or  furnace,  or,  when 
red  hot,  the  unsupported  parts  will  sag.  In  taking  such  pieces 
from  the  fire,  the  object  is  to  lift  the  edges  vertically  so  that  the 
lifting  shall  not  bend  them;  and  this  requires  considerable  skill, 
because  it  must  be  done  quickly,  or  parts  will  become  cooled 
and  will  warp,  as  well  as  not  harden  so  much  as  the  hotter 
parts. 

Quenching  for  Hardening. 
"We  now  come  to  the  cooling  or  quenching,  which  requires 


FIG.  62. — MILLING  CUTTER. 


THE    HARDENING   OF    STEEL. 


101 


as  much  skill  as  the  heating  to  prevent  warping  and  cracking, 
and  to  straighten  the  article  as  much  as  possible  during  the  cool- 
ing process.  The  cooling  should  be  performed  with  the  view  to 
prevent  the  contraction  of  the  metal  from  warping  the  weaker 
parts ;  and  to  aid  this,  in  cutters  of  the  type  shown  in  Fig. 
62,  tooth  parts  are  sometimes  made  a  little  hotter  than  the 
more  solid  parts  of  the  article,  the  extra  heat  required 
to  be  extracted  compensating  in  some  degree  for  the  di- 
minution of  the  sectional  area  from  which  the  heat  must '  be 
extracted.  Water  for  cooling  must  be  kept  clean,  and  in  that 


PIG.  63. — STAY   BOI/T   TAP. 

case  becomes  better  from  use.  It  may  be  kept  heated  to  about 
100  deg.  F.,  which  will  diminish  the  risk  of  having  the  article 
crack;  any  corners  should  be  made  as  rounded  as  possible.  If 
the  water  is  very  cold,  and  the  heat  hence  extracted  very  rapidly 
from  the  outside,  the  liability  to  crack  is  increased ;  and  in  many 
cases  the  water  is  heated  to  nearly  the  boiling  point,  so  as  to 
retard  the  extraction  of  the  heat.  Since,  however,  the  hardening 
of  the  steel  is  due  to  the  rapid  extraction  of  its  heat,  increasing 
the  temperature  of  the  water  diminishes  the  hardness  of  the 


FIG.    64. — SPIRAL  LIPPED   REAMER. 

steel,  and  it  is  necessary  to  counteract  this  effect  as  far  as  possi- 
ble, which  is  done  by  adding  salt  to  the  water.  .  .  .  All  arti- 
cles that  are  straight  or  of  the  proper  form  while  leaving  the 
fire  should  be  dipped  vertically  and  lowered  steadily  into  the 
water ;  and  if  of  weak  section  or  liable  to  crack  or  warp,  they 
should  be  held,  quite  still,  low  down  in  the  water  until  cooled 
quite  through  to  the  temperature  of  the  water.  If  the  article 
is  taken  from  the  water  too  soon,  it  will  crack,  and  this  is  a 
common  occurrence,  the  cracking  often  being  accompanied  by  a 


102 


HARDENING,    TEMPERING   AND   ANNEALING. 


sharp,  audible  "click."  Pieces  of  blade  form  should  be  dipped 
edgeways,  the  length  of  the  article  lying  horizontally  and  the 
article  lowered  vertically  and  held  quite  still,  because,  by  mov- 
ing it  laterally,  the  advancing  side  becomes  cooled  the  quickest, 
and  warping  and  cracking  may  ensue.  Straight  cylindrical  pieces 


Sellers  Hob. 


Short  Shank  Hob         I,ong  Taper  Die  Tap 
for  Sizing  Dies.        for  Cutting  Solid  Dies. 


FIG.  65. — HOBS  OR  MASTER  TAPS. 


THE    HARDENING   OF    STEEL.  1 03 

are  dipped  endwise  and  vertically.  When,  however,  the  dipping 
process  is  performed  with  a  view  to  leave  a  sufficient  heat  in  the 
body  of  the  article  to  draw  to  a  lower  temper  the  part  dipped, 
the  method  of  proceeding  is  slightly  varied." 

The  Hardening  of  Long  Slender  Tools. 

In  order  to  harden  long  slender  tools,  such  as  stay-bolt  taps, 
"hob"  taps  and  long,  taper  die  taps,  for  instance,  so  as  to  not 
require  subsequent  straightening  or  grinding,  care  is  necessary  in 
the  machining  as  well  as  the  hardening  operations.  It  is  not  de- 
sirable to  use  the  highest  carbon  steel  when  a  large  tool  is  to  be 
made  if  the  hardening  method  given  below  is  to  be  used. 

Have  the  stock  for  the  tool  about  y§  inch  larger  than  the 
finish  diameter  and  rough  down  to  within  1-16  inch  of  size.  Then 
pack  in  an  iron  box  in  powdered  charcoal  and  reheat,  heating 
to  a  red  and  being  sure  to  heat  evenly  and  slowly.*  This  will  re- 
move all  strains  which  may  have  taken  place  in  the  steel  during 
the  manufacture.  The  slower  the  steel  cools  the  better  will  be 
the  results  in  the  hardening,  as  it  may  be  heated  to  a  lower  heat 
which  will  have  a  tendency  to  refine  it. 

Sometimes  when  the  rough-down  blanks  for  long  tools  have 
been  annealed  by  the  method  described  above,  upon  taking  them 
from  the  annealing  box  some  will  be  found  to  have  sprung.  When 
this  occurs  do  not  attempt  to  straighten  while  cool,  but  instead, 
if  possible,  turn  the  bulge  out.  If  this  cannot  be  done,  heat  to  a 
cherry  red  and  straighten  while  hot  and  re-anneal.  After  finish- 
ing, test  the  tool  for  trueness,  and  then  harden  as  follows : 

Have  a  box  large  enough  to  allow  the  tools  to  stand  upright 
and  to  leave  lots  of  space  for  packing  at  the  top,  bottom  and  sides. 
Pack  the  packing  material  around  tightly,  put  the  lid  on  the  box 
and  heat  thoroughly  through,  testing  for  heat  with  test  rods,  and 
when  the  proper  heat  is  obtained  hold  it  for  a  few  hours,  then 
remove  the  box  and  draw  the  tools  carefully  from  the  pack  with 
a  pair  of  tongs  and  quench  in  a  bath  of  raw  linseed  oil  which 
may  be  kept  at  a  sufficient  low  temperature  by  some  simple  cool- 
ing arrangement. 

When  dipping  the  heated  tools  quench  straight  down  into  the 
center  of  the  oil  and  move  vertically  until  a  black  appears,  when 
they  may  be  moved  to  the  edsfe  of  the  bath  tank.  In  an  oil  bath 
the  contents  should  be  po-itated  so  that  the  oil  will  circulate  and 
flow  toward  the  center,  thus  keeping  the  vapor  generated  by  con- 


IO4 


HARDENING,    TEMPERING   AND    ANNEALING. 


tact  of  the  heated  steel  and  oil  away  from  the  work.     By  doing* 
this  there  will  be  no  soft  spots  in  the  wcrk  when  hardened. 

Hardening  Small  Parts  and  Long   Thin  Parts. 
When  a   large  number  of  very   small   parts,   such   as   cutter 
blades  of  the  type  shown  in  Fig.  66,  are  to  be  hardened  they 


FIG.  66. — PATENT   SQUARE   THREADING   TOOL. 

should  be  packed  in  closed  iron  boxes,  and  the  box  heated. 
When  all  the  parts  have  reached  the  proper  heat,  they  should  be 
dumped  into  the  quenching  bath,  of  either  oil  or  water,  as  the 
nature  of  the  work  may  require.  Another  way  by  which  small 
parts  may  be  heated  uniform  is  by  means  of  a  lead  bath.  Keep 


FIG.  67. — COMBINED   DRILL   AND   COUNTERSINK. 

the  lead  at  the  proper  heat  and  cover  the  top  with  powdered  char- 
coal and  coke. 

Very  small  tools,  such  as  small  piercing  punches,  etc.,  should 
be  hardened  in  an  oil  bath  or  in  luke  warm  water,  as  if  cold 
water  is  used  they  will  cool  too  quickly  and  come  out  of  the  bath 
cracked  or  so  brittle  as  to  be  useless.  Never  heat  a  piece  of  steel 
for  hardening  hot  enough  to  ra:se  scale  on  it;  even  when  it  is 


THE    HARDENING    OF    STEEL. 


105 


a  very  large  piece  this  can  be  overcome  by  heating  very  slowly 
in  a  packing  box.  When  steel  has  been  heated  too  hot  and  then 
quenched,  the  grain  is  rendered  coarse  and  brittle,  and,  although 
it  may  be  drawn  to  the  desired  temper,  it  will  break  quicker  than 


FIG.  68. — TWIST  DRILL. 


a  piece  which  has  been  hardened  at  a  very  low  heat  and  not  tem- 
pered at  all,  although  the  piece  which  was  heated  too  hot  and 
hardened  and  drawn  will  be  softer  than  the  other  piece. 

When  hardening  long,  flat  or  round  objects  they  should  be 


FIG.  69. — TWIST   DRILL. 

dipped  endwise,  holding  them  perpendicular  with  the  surface  of 
the  bath.  When  this  is  done  the  articles  will  come  out  perfectly 
straight,  or  at  least  very  little  sprung.  When  dipped  otherwise 
such  tools  will  warp.  When  dipping  a  half-round  tool  dip  it  with 


FIG.  70. — TURRET  REAMER  FOR  FINISHING. 

the  half-round  side  at  an  angle  of  about  twenty  degrees  with  the 
surface  of  the  water  and  it  will  come  out  either  almost  straight, 
or  straight. 


IO6  HARDENING,    TEMPERING    AND    ANNEALING. 

Hardening  in  Solutions. 

In  order  to  harden  a  large  number  of  steel  tools  or  pieces  so 
that  uniform  hardness  and  temper  will  be  attained,  and  so  that 
the  steel  will  come  out  of  the  process  white  and  clean,  as  is  often 
required,  the  following  process  may  be  adopted:  First,  in  the 
heating  of  the  steel,  a  solution  which  will  project  it  from  the 
fire  and  another  to  chill  it  quickly  are  necessary.  This  last 
solution  will  also  give  the  desired  clean  white  appearance  to  the 
steel.  The  receipt  for  this  first  solution  is,  equal  quantities  of  sal- 
soda  and  borax  in  water  containing  one  ounce  of  cyanide  of 
potassium  to  the  gallon.  For  the  second  solution,  a  strong  brine 
made  of  salt  and  water,  and  about  the  same  amount  of  cyanide 
as  salt,  will  do.  Have  the  water  hot  and  add  about  two  ounces 
of  sulphuric  acid  to  each  gallon  of  water  used ;  when  mixed,  put 
away  in  a  cool  place  and  keep  well  covered. 

To  use  the  solutions  proceed  as  follows:  Fill  all  holes  near 
the  edge  of  the  steel  with  fireclay,  then  dip  into  the  first  solution 
and  place  the  steel  immediately  on  the  fire  while  wet.  Heat 
slowly  and  carefully  and  be  sure  not  to  heat  any  one  portion  of 
the  work  faster  than  another,  as  the  slower  the  heat  the  more 
uniform  its  distribution  in  the  piece.  When  the  proper  tempera- 
ture has  been  reached,  which  should  be  a  clear  bright  red,  dip 
the  work  straight  down  into  the  hardening  solution;  when  it 
has  cooled,  remove  from  the  bath,  and  work  of  silvery  whiteness 
and  uniform  hardness  will  be  the  result.  When  heating  long 
slender  pieces  in  this  solution,  dip  them  endwise,  and  do  not  shake 
about,  but  instead,  revolve,  if  possible,  rapidly. 

Heating  in  Hot  Lead  for  Hardening. 

There  is  a  large  class  of  work  which  can  be  best  heated  for 
hardening  in  red-hot  lead.  It  is  a  very  rapid  and  satisfactory 
method  for  such  tools  as  small  counter-bores,  reamers,  shank, 
mills,  knurls  and  parts  such  as  bicycle  cones,  balls,  cups,  and  sew- 
ing machine  and  typewriter  parts.  What  makes  the  lead  par- 
ticularly valuable  for  heating  such  parts  is  that  a  uniform  heat 
can  be  applied  without  danger  of  burning  or  scaling  the  inside  be- 
fore the  center  is  heated. 

When  heating  in  lead  a  graphite  crucible  placed  so  that  a 
uniform  heat  will  be  maintained  beneath  and  around  the  pot  will 
prove  the  best.  As  to  the  lead  to  use,  care  must  be  taken  to  get 
a  brand  with  as  little  sulphur  in  it  as  possible.  Never  use  scrap 


THE    HARDENING    OF    STEEL. 


107 


lead,  as  it  will  ruin  the  steel.   Chemically  pure  lead  should  always 
be  used. 

There  are  a  great  many  compounds  in  use  to  prevent  the  lead 
from  sticking  to  the  work.  One  of  the  best  is  the  following :  One 
pound  of  powdered  cyanide  dissolved  in  one  gallon  of  boiling 


FIG.    71. — HEAVY    KNURLS. 

water ;  allow  to  cool,  and  then  dip  the  articles  to  be  heated  in  the 
solution;  remove  and  allow  to  dry  thoroughly  before  putting 
them  into  the  lead.  Moisture  will  make  the  lead  fly. 

Small  articles  of  an  even  size  and  thickness  throughout  can 
be  put  into  the  lead  cold,  while  irregular  pieces  must  be  heated 


FIG.  72. — DOUBLE   KNURLING  TOOL. 

nearly  red  before  putting  into  the  lead  in  order  to  prevent  un- 
equal expansion. 

By  keeping  the  surface  of  the  lead  covered  with  broken  char- 
coal, drops  will  be  prevented  from  forming.  After  the  heating 
has  been  concluded  empty  the  crucible. 


IO8  HARDENING,    TEMPERING    AND    ANNEALING. 

To  get  good  results  when  hardening  by  heating  in  lead,  stir 
the  liquid  occasionally  so  as  to  equalize  the  heat,  as  the  bottom 
will  always  be  hotter  than  the  top.  When  tools  or  parts  with 
fine  projections  or  teeth  are  heated,  take  a  stiff  brush  and  clean 
off  any  particles  of  lead  which  may  stick  in  them  before  quench- 
ing. This  is  necessary  as  steel  will  not  harden  when  lead  has 
stuck  to  it,  as  the  spots  do  not  come  in  contact  with  the  bath. 

Hardening  Metal  Saws. 

To  harden  metal  saws  or  articles  of  a  similar  nature,  provide 
a  pair  of  flat  cast-iron  plates  and  oil  the  faces  well  with  a  heavy 
oil.  Heat  the  saws  in  a  box  or  some  other  arrangement  which 
will  prevent  the  fire  from  coming  in  contact  with  them  (a  flat 
plate  will  do)  and  prevent  the  article  from  warping  during  the 


FIG.  73. — METAL  SAW. 

heating  process.  When  heated  to  a  bright  red  remove  the  article 
and  place  it  on  the  lower  oiled  plate  and  drop  the  other  plate  on 
it  quickly,  and  hold  it  down  until  the  article  is  cold.  If  a  pair 
of  hinged  plates  are  used  one  man  can  do  the  job;  if  not,  two 
will  be  required. 

Mixture  to  Prevent  Lead  from  Sticking. 
The  formula  here  given  is  taken  from  the  report  of  the  Chief 
of  Ordnance  of  the  United  States  War  Department,  and  is  used 
when  hardening  files,  and  has  also  given  good  results  when  hard- 
ening small  taps,  milling  cutters,  reamers,  broaches,  rotary  files 
and  similar  tools  having  fine  teeth.  The  following  is  a  copy  of 
the  report: 


THE    HARDENING    OF    STEEL.  1 09 

"Before  hardening,  the  files  are  treated  with  a  mixture  of  salt 
and  carbonaceous  materials  to  protect  the  teeth  from  decarboniza- 
tion  and  oxidation.  The  kinds  and  proportions  of  the  ingredients 
are  given  in  the  following  table : 

"Pulverized  and  charred  leather I      pound. 

"Fine  family  flour ij^  pounds. 

"Fine  table  salt 2      pounds. 

"The  charcoal  made  from  charred  leather  should  be  triturated 
until  fine  enough  to  pass  through  a  No.  45  sieve. 

"The  three  ingredients  are  thoroughly  mixed  and  incorporated 
while  in  a  dry  state  and  water  is  then  added  slowly  to  prevent 
lumps,  until  paste  formed  has  the  consistency  of  ordinary  varnish. 
When  ready  the  paste  is  applied  to  the  file  with  a  brush,  care 
being  taken  to  have  the  teeth  well  filled  with  the  mixture.  The 
surplus  paste  is  then  wiped  off  the  file  by  the  brush  and  the  file 
is  placed  on  end  before  a  slow  fire  to  dry.  If  dried  too  quickly, 
the  paste  will  crack  or  blister;  if  not  dried  enough,  the  remain- 
ing moisture  will  be  transformed  into  steam  when  dipped  into 
the  heated  lead  bath  and  cause  an  ebullition  or  sputtering  of  the 
lead,  throwing  out  minute  globules  of  the  latter  which  may  en- 
danger the  eyes  of  the  operator.  The  fusing  of  the  paste  upon 
the  surface  of  the  file  indicates  the  proper  heat  at  which  the  file 
should  be  hardened." 

Hardening  Long  Taper  Reamers. 

The  hardening  of  long  taper  reamers  of  small  diameter,  so 
as  to  prevent  them  from  coming  through  curved  or  twisted,  is  one 
of  the  most  difficult  operations  for  the  hardener,  and  we  can  only 
advise  the  necessary  precautions  used  by  those  who  succeed  with 
such  work.  The  steel  should  be  annealed  a  second  time  before 
the  finishing  cut  is  taken,  by  heating  slowly  in  a  low  fire  by  pack- 
ing it  in  an  iron  box  or  tube  with  powdered  charcoal,  fine  sand, 
or  clean  ashes ;  then  finished.  The  heating  for  hardening  should 
be  done  in  the  same  manner  as  the  re-annealing.  When  the  box 
and  reamer  have  been  heated  thoroughly  to  a  bright  cherry  red  the 
reamers  should  be  carefully  drawn  out  endwise,  so  as  to  prevent 
the  possibility  of  bending  while  hot;  and  immediately  quenched 
vertically  in  an  oil  bath.  Any  variation  from  a  vertical  position 
while  dipping  is  liable  to  warp  the  work,  through  one  side  cool- 


IIO  .         HARDENING,    TEMPERING    AND   ANNEALING. 

ing  faster  than  the  other.  In  drawing  temper,  care  should  be 
taken  to  heat  evenly  on  all  sides,  so  as  to  bring  them  to  the  same 
straw  color,  brown  or  light  blue,  according  to  whatever  use  the 
tool  is  to  be  put.  Long  delicate  reamers  should  always  be  ground 
to  size  after  the  hardening  and  tempering  operations. 

The  Use  of  Clay  in  Hardening. 

Very  often  in  die  and  tool  work  it  is  desired  that  a  piece  with 
a  hole  in  the  center  should  be  hard  around  the  outside  and  soft 
around  the  hole,  or  a  punch  is  required  to  be  hard  at  both  ends 
and  soft  in  the  center.  To  accomplish  these  results  with  ease 
use  clay  in  the  following  manner:  When  the  stock  around  the 
hole  is  to  be  left  soft  and  the  outer  edges  of  the  piece  hardened, 
fill  the  hole  with  clay  and  pad  it  at  both  sides,  then  heat  the  piece 
and  plunge  it  into  the  water.  When  cool,  remove  the  clay  and 
the  stock  around  the  hole  will  be  found  to  be  soft  while  the  edges 
will  be  as  hard  as  required.  To  harden  both  ends  of  the  punch 
and  leave  the  center  soft,  put  a  bandage  of  clay  around  the  center, 
or  desired  soft  portion,  about  ^4  of  an  inch  thick  and  bind  it 
with  a  piece  of  thin  sheet  metal.  Heat  and  quench,  and  the  de- 
sired result  will  be  accomplished. 

When  hardening  dies  or  other  press  tools  in  which  there  are 
holes  near  the  edges  of  the  work,  fill  the  holes  with  clay  before 
heating  and  the  tendency  to  crack  will  be  overcome.  When  the 
holes  are  not  filled  with  clay  (when  the  steel  is  quenched)  steam 
generates  in  the  holes  and  cracks  start,  or  excessive  warping  oc- 
curs, due  to  the  fact  that  the  steam  does  not  escape  fast  enough 
and  the  contracting  of  the  metal  is  unequal. 

Special  Instructions  for, Hardening  and  Tempering. 

Often  when  tool  steel  is  brought,  special  instructions  will  be 
given  as  to  the  method  of  hardening  and  tempering  it.  Some- 
times these  instructions  are  followed  out  and  oftener  they  are 
not.  Now  in  all  cases  when  such  instructions  are  given,  don't 
forget  to  go  by  them,  otherwise  do  not  buy  that  brand  of  steel, 
but  instead  secure  a  brand  which  you  can  harden  as  you  think 
best.  There  are  various  brands  of  steel  on  the  market  which  are 
used  for  a  number  of  special  purposes  and  which  possess  qualities 
which  other  brands  do  not  (in  regard  to  cutting  at  rMgh  speeds, 
removing  large  amounts  of  stock,  etc.)  which  require  hardening 


THE    HARDENING    OF    STEEL.  Ill 

at  different  temperatures  and  tempering  at  special  colors.  If  you 
require  this  sort  of  steel  for  any  special  purpose,  don't  try  to  find 
out  why  the  special  instructions  are  given,  but  do  as  directed,  and 
if  the  results  are  what  the  makers  claim  for  it,  it.  does  not  make 
any  difference  if  you  have  to  harden  it  in  a  cake  of  soap — the 
result  is  the  thing. 

Hardening  and  Tempering  Round  Thread  Dies. 

A  good  way  to  harden  and  temper  round  thread  dies  of  the 
type  shown  in  Fig.  74  is  to  proceed  as  follows :  The  die  after 
having  been  drilled,  worked,  filed,  etc., 
should  be  split  at  D,  leaving  about  1-32  inch 
of  wall  as  shown.  Heat  carefully  and 
quench  in  water  bath,  after  which  polish  the 
sides.  To  temper  use  the  lead  bath.  Enter 
the  die  into  the  bath  edgeways  up  to  about 
the  dotted  line  shown  in  Fig.  74.  After 
holding  it  in  the  bath  for  about  a  minute  re-  FIG.  74 — THREAD  DIE;. 
move  and  examine.  If  the  heating  has  been 

done  correctly  the  part  A  will  have  turned  blue  while  the  point 
E  will  not  be  drawn  at  all.  Treat  B  likewise,  and  in  turn  C  and  D. 
When  this  is  done  properly  there  will  be  sufficient  heat  contained 
in  the  outer  portion  to  gradually  draw  and  temper  the  point  E, 
which  may  be  anything  from  a  light  yellow  to  a  dark  yellow,  as 
the  case  may  require.  In  the  tempering,  a  few  drops  of  lard  oil 
on  the  teeth  at  intervals  when  required  will  check  the  temper 
and  prevent  it  from  running  out  further  at  one  point  than  an- 
other. A  little  practice  will  teach  the  operator  how  much  heat 
to  subject  the  outside  portion  of  the  die  to  so  as  to  allow  of  all  the 
point  E  coming  to  the  same  temper. 

After  the  tempering  process  the  die  may  be  repolished  and 
then  the  wall  left  at  D  removed  by  grinding  with  a  thin  emery 
wheel,  or  by  entering  a  small  narrow  face  set  and  hitting  it.  a 
sharp  blow,  when  the  wall  will  break  but.  The  reason  for  leaving 
the  thin  wall  at  D  is  to  hold  the  ends  firm  while  hardening, 
thus  preventing  excessive  shrinking  and  warping.  Split  bush- 
ings may  be  hardened  in  the  same  manner. 

Hardening  Bushings,  Shell  Reamers,  Hobs,  Etc. 
A  device  useful  in  the  hardening  of  bushings,  shell  reamers, 


112 


HARDENING,    TEMPERING    AND    ANNEALING. 


<&' 


FIG.  75. — USEFUL 
HARDENING   DEVICE. 


hobs,  etc.,  is  shown  in  Fig.  75,  and  consists 
of  a  piece  of  drill  rod,  R,  threaded  about  an 
inch  longer  than  the  length  of  the  article  to 
be  hardened,  and  nut  and  washer  located  as 
shown.  The  dotted  lines  show  the  work  to 
be  hardened,  AAAA,  asbestos  washers,  BB, 
common  iron  washers,  the  whole  being  held 
together  between  the  two  nuts.  Heat  the 
entire  arrangement  to  the  proper  tempera- 
ture and  quench  in  water  in  the  usual  man- 
ner. By  using  a  device  of  this  sort  an  up- 
ward flow  of  water  through  the  article  is 
prevented,  as  is  the  consequent  sudden  chill, 
thus  eliminating  to  a  certain  extent  tfhe  tend- 
ency to  warp  or  crack.  In  such  tools  in 
which  the  outside  only  is  desired  to  be  hard- 
ened, the  method  is  an  excellent  one,  as  the 
inside  will  remain  comparatively  soft,  unless 
very  thin,  when  it  will  harden  clear  through. 

Hardening  and  Tempering  Collet  Spring  Chucks. 
The  following  kink  we  have  found  very  handy  when  making 
collet  spring  chucks  of  the  shape  shown  in  Fig.  76.    After  finish- 
ing them  in  the  lathe,  leaving,  of 
course,    enough    stock   to   lap   and 
grind  to  a  finish,  face  them  on  an 
arbor  and  saw  the  spring  slots  as 
shown;  that  is,  at  the  end  of  each 
slot,   as   shown   at  T   and  V.     In- 
stead of  cutting  completely  through 
at  this  point,  leave  a  very  thin  wall 
about  y%   inch  long  at  the  end  of 

the  cuts.  Then  harden  and  temper  the  chucks  as  desired,  and 
after  lapping  the  inside  to  size,  place  on  an  arbor  and  grind  the 
tapers  as  required;  then  take  a  small,  narrow  broach  and  by 
entering  it  into  the  slots  and  hitting  it  a  sharp  blow  with  a  ham- 
mer the  thin  wall  will  break  through.  This  kink  I  have  used 
to  the  best  advantage  in  shops  which  had  no  grinding  facilities. 
When  proceeding  as  aforesaid  it  was  possible  to  finish  the  outside 
and  taper  to  size  before  hardening  without  the  possibility  of  the 
•chucks  running  out  to  any  noticeable  extent.  Of  course  for 


FIG.  76. — SMALL   COLLET 
SPRING   CHUCK. 


THE    HARDENING   OF    STEEL.  113 

work  of  the  utmost  accuracy  this  method  would  not  do.  But 
then  again  work  of  the  utmost  accuracy  is  not  accomplished  in 
shops  where  the  tool  facilities  are  not  up  to  date. 

The  Taylor-White  Process  for  Treating  Steel. 

In  the  September,  1901,  number  of  the  Journal  of  the  Franklin 
Institute  was  published  a  paper  by  Charles  Day  upon  the  Taylor- 
White  process  for  treating  tool  steel,  and  the  results  obtained 
with  steel  so  treated,  at  the  works  of  the  Link  Belt  Engineering 
Company,  Philadelphia,  Pa.  When  this  process  was  first  an- 
nounced facts  were  given  and  quoted  reports  of  tests  made  at  the 
works  of  the  Bethlehem  Steel  Company,  Bethlehem,  Pa.,  where 
the  process  was  developed  by  Messrs.  Taylor  and  White.  The 
paper  by  Mr.  Day  gives  information  upon  air  hardening  steels  in 
general  before  reverting  to  the  subject  of  steel  treated  by  the 
Taylor- White  process. 

Mr.  Day  says  that  air-hardening  steels  have  unquestionably 
replaced  the  carbon  variety  for  roughing  work,  the  efficiency  of 
the  former  ranging  from  one  and  one-half  to  twice  that  of  the 
latter.  This  gain  is  because  air-hardening  steels  hold  their  cut- 
ting edge  at  much  higher  temperatures  than  carbon  steels  and 
consequently  can  be  worked  at  proportionately  greater  cutting 
speeds.  The  usual  method  of  hardening  air-hardening  steels  is 
well  known,  manufacturers  usually  placing  a  great  stress  on  the 
fact  that  the  tool  must  be  heated  over  a  cherry  red,  otherwise  it 
will  be  burned  and  so  ruined.  The  object  of  Messrs.  Taylor  and 
White  was  to  obtain  some  exact  knowledge  on  this  matter,  and 
extensive  experiments  were  conducted  in  the  belief  that  a  tool 
steel  could  be  produced  to  give  still  better  results  than  those 
already  obtained. 

The  new  process  depends  upon  the  fact  that  although  both 
carbon  and  air-hardening  steels  deteriorate  rapidly  when  the  tem- 
perature rises  above  a  cherry  red,  there  are  some  chemical  com- 
positions that  may  be  used  for  air-hardening  steels  which  are 
much  improved  as  cutting  tools  if  they  are  raised  to  a  higher 
temperature  in  the  hardening  process.  Their  maximum  efficiency 
is  reached  when  the  steel  is  heated  to  a  point  where  it  crumbles 
when  tapped  with  a  rod.  The  point  to  which  air-hardening  steel 
was  formerly  heated  in  the  process  of  hardening  is  between  1,500 
and  i, 600  deg.  F.,  and  is  called  the  breaking-down  point.  Steel 
liaving  the  new  treatment  is  heated  to  2,000  deg.  F.  The  com- 


114  HARDENING,    TEMPERING    AND    ANNEALING. 

position  found  to  give  the  best  results  consists  of  an  air-harden- 
ing steel  containing  about  i  per  cent  of  chromium  and  4  per  cent 
of  tungsten ;  while  for  very  hard  metals,  such  as  the  chilled  scale 
on  cast-iron,  etc.,  3  per  cent  of  chromium  and  6  or  more  per  cent 
of  tungsten  are  good.  The  variation  in  carbon  seems  to  matter 
but  little,  steel  varying  from  85  to  200  points  giving  equally  good 
results. 

The  tool  is  cooled  rapidly  from  the  "high  heat"  (2,000  de- 
grees) to  a  point  below  the  breaking-down  temperature,  in  a  lead 
bath,  and  then  slowly  in  the  air,  or  lime,  etc.,  as  the  case  may  be. 
It  is  essential  that  at  no  time  the  temperature  should  rise,  as  in 
such  a  case  the  tool  would  be  seriously  impaired.  After  the 
steel  has  cooled  off,  its  efficiency  is  found  to  be  further  increased 
by  subjecting  it  to  what  is  termed  the  "low  heat"  for  about  ten 
minutes;  this  temperature  ranging  from  700  deg.  to  1,240  deg. 
F.  After  cooling  from  the  "low  heat"  the  tool  is  ready  for  use. 
It  is  not  essential  to  anneal  the  steel  when  reforging  and  the  tools 
can  be  worked  with  comparative  ease. 

In  the  operation  of  the  Taylor- White  process  apparatus  is 
employed  by  means  of  which  temperature  can  be  controlled  within 
very  narrow  limits,  which  accounts  for  the  uniformity  of  results 
obtained  with  the  tools  treated  by  this  process. 

About  97  per  cent  of  the  material  worked  upon  at  the  shops  of 
the  Link  Belt  Engineering  Company  is  cast-iron.  In  order  to 
make  a  rough  test  on  cast-iron  one  tool  was  obtained  from  Bethle- 
hem and  put  to  work  on  a  7-foot  boring  mill  turning  the  inside 
of  a  cast-iron  ring.  The  time  required  to  do  this  work  with  their 
old  tools  had  been  determined  many  times  in  setting  piece  rates, 
and  was  about  fourteen  hours.  With  the  Taylor-White  tool  the 
time  was  reduced  to  three  and  one-half  hours,  and  a  gain  of  75 
per  cent  made.  While  steel  used  heretofore  was  not  the  best  ob- 
tainable, and  was  probably  not  worked  to  its  highest  efficiency, 
there  was,  nevertheless,  a  large  saving  due  to  the  new  steel. 

Some  interesting  data  was  also  obtained  from  an  order  of 
rope  sheaves,  the  time  required  on  similar  work  having  been  tabu- 
lated for  several  years.  The  average  time  required  to  machine 
thirteen  sheaves  with  the  old  tools  was  nine  and  one-half  hours ; 
the  same  for  sixteen  similar  sheaves,  the  roughing  being  done  by 
Taylor- White  tools,  was  five  hours  and  five  minutes,  or  a  saving 
of  46^2  per  cent. 

Assuming,  however,  the  time  for  setting  up,  forming,  boring 


THE    HARDENING   OF    STEEL.  115 

and  polishing  the  same  when  the  sheaves  were  finished  with  old 
tools  as  with  the  treated  tools,  since  the  latter  are  not  suitable  for 
cutting  finishing  cuts,  the  time  for  roughing  would  have  been 
7.85  hours  and  a  saving  of  56.3  per  cent  was  made  in  operations 
where  it  was  possible  to  use  treated  tools. 

In  order  to  obtain  some  data  with  regard  to  pressure  on  the 
points  of  tools  for  given  depth  of  cuts,  feed,  etc.,  and  at  the 
same  time  to  show  the  effect  of  the  treatment,  a  cast-iron  ring 
six  and  one-half  feet  in  diameter  was  bolted  to  the  table  of  a 
seven-foot  mill.  The  first  tool  used  was  one  treated  for  hard 
material.  It  cut  106  pounds  of  metal  in  10  minutes,  and  when 
removed  was  in  perfect  condition.  A  "Mushet"  tool  under  the 
same  condition  lasted  but  one  minute,  and  removed  5^2  pounds 
of  metal.  The  actual  pressure  against  the  tool  in  each  case  ex- 
ceeded 3^4  tons,  while  the  pressure  per  square  inch  with  another 
self-hardening  tool  was  143,000  pounds. 

Eighteen  months  ago  a  50  horse  power  engine  supplied  the 
power  for  about  40  machine  tools  in  the  Link  Belt  Engineering 
Company's  works,  and  also  run  the  pattern  shop  and  grinding 
room.  The  actual  horse  power  developed  had  been  found  to 
average  45.  Of  this  27  horse  power  was  consumed  by  the  shaft- 
ing, leaving  but  18  horse  power  for  actual  work.  After  the  new 
tools  were  in  general  use  and  the  machine  pushed  to  obtain  the  de- 
sired results,  it  became  apparent  that  the  power  was  absolutely  in- 
adequate; indicator  cards  from  the  engine  frequently  showed 
an  overload  of  60  per  cent,  and  at  this  point  it  was  found  essen- 
tial to  put  motors  on  some  of  the  larger  tools. 

The  following  particulars  about  the  process  have  been  fur- 
nished by  the  Bethlehem  Steel  Company : 

"The  practical  speeds  at  which  these  tools  will  run  has  been 
found  to  be  from  two  to  four  times  that  of  any  steels  which  we 
have  experimented  with,  and  we  have  endeavored  to  obtain  the 
best  in  the  market. 

"The  process,  which  is  applied  after  the  tool  has  been  dressed 
or  machined  to  shape,  penetrates  to  the  center  of  the  steel,  even 
in  the  largest  tools  we  have  ever  treated,  i.  e.,  4  inches  square.  All 
of  the  standard  brands  of  self-hardening  steel  which  have  been 
experimented  with  are  improved  to  a  more  or  less  extent  by  the 
treatment ;  it  is  preferred,  however,  to  use  a  steel  of  special  com- 
position in  order  to  get  the  greatest  uniformity  and  maximum  re- 
sults. This  special  steel  forges  so  much  more  readily  than  the 


Il6  HARDENING,    TEMPERING    AND    ANNEALING. 

general  run  of  self-hardening  steels  that  tools  of  different  shapes 
may  be  easily  made  up. 

"We  have  also  discovered  a  simple  and  comparatively  rapid 
method  of  annealing  of  special  steel,  by  which  tools  may  be  easily 
machined  to  shape,  making  it  applicable  to  twist  drills,  chasers, 
inserted  cutters,  etc.,  which  have  theretofore  not  been  made  from 
self-hardening  steel. 

"A  great  advantage  in  the  use  of  these  tools  is  that  when  cut- 
ting dry  at  the  rate  of  maximum  efficiency  the  chips  should  come 
off  blue.-  These  blue  chips  enable  a  foreman  at  a  glance  to  tell 
whether  the  work  is  being  done  at  the  proper  speed  when  running 
under  water  at  the  proper  cutting  and  allowing  the  tool  to  cut 
dry  for  a  few  moments. 

"The  apparatus  used  in  the  Taylor-White  process  offers  also 
a  simple  and  effective  means  of  heating  any  other  tools  at  uniform- 
ity and  higher  qualities  in  this  class  of  steel,  as  well  as  self-hard- 
ening steel. 

"As  is  well  known,  tempering  steels  of  different  makes  and 
different  qualities  require  different  temperatures  for  hardening 
to  obtain  the  best  results ;  therefore,  by  means  of  our  apparatus, 
which  is  capable  of  closely  controlling  temperature,  these  points 
may  be  accurately  determined  for  each  class  of  steel,  and  made 
use  of  in  daily  practice.  The  operation  of  the  process  is  ex- 
tremely simple,  as  it  is  controlled  by  apparatus  which  regulates 
the  different  steps,  and  does  not  require  skill  or  expert  labor." 


CHAPTER    V. 

TEMPERING BY  COLORS IN  OIL ON   HOT  PLATES BY  THERMOM- 
ETER  IN    HOT    WATER IN    THE    SAND    BATH BY 

SPECIAL    METHODS. 

Tempering. 

In  the  term  "tempering"  we  include  all  processes  which  tend  to 
reduce  the  hardness  of  steel  to  a  degree  recognized  inside  the 
color  test  by  color,  and  also  all  processes  by  which  the  degree  of 
hardness  is  lowered,  modified,  tempered,  or  lessened.  It  is  wrong 
to  apply  the  term  "temper"  to  processes  which  at  one  operation 
leave  the  steel  harder  than  any  degree  of  the  color  test ;  a  process 
which  does  not  reduce  the  hardness  of  steel  to  a  degree  denoted 
by  some  color  in  the  color  test  should  be  termed  hardening. 

If  instead  of  the  color,  in  tempering,  the  degree  of  temperature 
required  were  given,  the  process  would  be  very  much  simplified. 
Thus  430  degrees  would  denote  the  same  degree  of  hardness  as  a 
faint  yellow  and  all  degrees  of  hardness  above  that  would  have 
to  be  specified  in  less  temperature,  while  all  degrees  of  softness 
down  to  a  blue  tinged  with  green  would  be  included  in  degrees 
of  temperature  up  to  630.  The  degrees  of  softness  below  that 
denoted  by  color  test  or  thermometer  are :  bright  red  in  the  dark, 
720  degrees;  red  hot  in  twilight,  884  degrees,  and  red  visible  by 
day,  1,077  degrees.  The  degrees  of  softness  below  them  are  indis- 
tinguishable by  the  test;  they  remain  unknown  quantities  of  de- 
grees, and  are  only  indicated  by  the  ease  with  which  the  metal 
can  be  machined. 

The  universal  adoption  of  thermometer  test  for  tempering  will 
remove  the  technical  objection  to  the  color  test,  i.  e.,  that  the 
color  obtained  on  the  piece  of  steel  through  heat  is  no  indication 
that  the  steel  possesses  any  above  its  natural  degree  of  hardness ; 
as  steel,  wrought  iron  and  cast  iron  will  assume,  when  polished 
and  heated  to  the  necessary  degree  of  temperature,  all  the  colors 
of  the  test.  Thus  the  color  on  a  piece  of  steel  is  simply  an  indi- 
cation that  it  has  been  heated  to  a  certain  degree,  not  that  it  is 
tempered,  or  in  fact  that  the  heating  process  has  in  any  way 
changed  the  degree  of  hardness  or  softness. 


Il8  HARDENING,    TEMPERING    AND    ANNEALING. 

Tempering  when  done  by  a  second  operation  modifies  the 
hardness  imparted  to  the  steel  by  the  first  one  and  depends  for  its 
uniformity  upon  the  uniformity  of  the  first  process.  For  instance, 
if  a  number  of  pieces  of  steel  of  uniform  grade  are  heated  to  the 
same  degree  of  temperature,  and  quenched  in  water  until  cold, 
then  removed,  then  tempered  to  the  same  color,  they  will  of  course 
be  possessed  of  an  equal  degree  of  hardness ;  but  if  other  pieces 
of  steel  of  a  different  carbon  percentage  are  subjected  to  exactly 
the  same  process  in  all  its  details,  leaving  upon  them  the  same 
temper  color,  they  will  not  possess  the  same  degree  of  hardness 
as  those  of  the  first  lot.  From  this  we  learn  that  temper  colors 
may  be  proof  of  equality  in  the  degree  of  temper  in  pieces  of  the 
same  steel,  but  the  same  is  not  indicative  of  any  uniform  degree 
of  hardness  in  different  steels. 

In  the  hardening  of  inexpensive  cutting  tools  the  above  facts 
make  very  little  difference,  as  for  such  tools  special  brands  of  steel 
are  procurable  which  will  harden  sufficiently  to  give  accuracy  to 
the  color  test  of  tempering,  when  heated  to  any  degree  of  heat  from 
a  blood  red  to  a  yellow  red ;  the  difference  in  hardness  in  the 
steel,  when  quenched  at  either  degrees  of  heat  being  too  small 
to  entitle  them  to  consideration  in  tools  which  are  inexpensive  to 
make. 

In  the  tempering  of  special  tools  the  exact  degree  of  temper 
which  experiment  has  determined  must  be  given.  A  tool  user 
knows  that  in  the  shade  of  yellow  in  the  color  test  alone  enter  over 
a  range  of  70  degrees,  and  that  within  these  70  degrees  lies  a  wide 
range  of  hardness.  It  is  much  better  to  adopt  a  tempering  process 
that  will  determine  with  accuracy  the  first  heating  temperature, 
as,  for  instance,  the  heating  of  a  tool  in  melted  lead,  melted  salt, 
or  melted  glass  and  then  quenching  it  into  a  cooling  bath  the  tem- 
perature of  which  may  be  maintained  by  suitable  means,  and  then 
drawing  the  temper  in  a  bath  of  oil  heated  to  and  maintained  at  the 
degree  of  temperature  required.  When  such  methods  are  used, 
if  the  steel  used  is  of  a  brand  which  experience  in  using  has  taught 
to  be  uniform,  the  greatest  obtainable  accurate  degree  of  temper 
will  be  obtained  in  both  the  operations,  and  the  tools  will  be  hard- 
ened better  and  more  reliable  than  could  be  obtained  under  the 
color  test. 

In  most  establishments  where  large  numbers  of  hardened  tools 
or  parts  are  required  the  methods  described  are  in  use;  but 
when  the  articles  are  large  or  only  a  few  small  parts  at  intervals 


TEMPERING.  119 

are  required,  it  would  not  of  course  pay  to  keep  the  heating  ar- 
rangements constantly  ready.  It  is  then  that  the  open  fire  and  the 
color  test  must  be  adopted.  It  is  under  the  latter  conditions  that 
the  skill,  experience,  and  judgment  of  the  hardener  are  called 
into  use,  as  from  the  time  the  steel  is  put  in  the  fire  until  it  is 
quenched  and  tempered,  upon  him  depends  absolutely  the  entire 
success  of  the  operations. 

Tempering  in  the  Sand  Bath. 

When  a  number  of  pieces  of  the  same  size  or  of  slightly  dif- 
ferent sizes  have  been  hardened  and  it  is  desired  to  draw  them 
all  to  the  same  temper,  the  sand  bath  will  be  found  to  give  the 
most  uniform  results.  This  consists  of  an  iron  box  filled  with 
sand  and  heated  over  the  fire  or  in  a  muffle  to  the  temperature  re- 
quired. When  the  sand  has  been  heated  to  the  required  degree, 
the  tools  to  be  tempered  are  lowered  into  it  and  removed  when 
the  color  denoting  the  temper  required  appears. 

The  Effects  of  Slow  Heating  and  Tempering. 
Always  remember  that  the  slower  the  temper  is  drawn,  the 
tougher  the  steel  will  be.  When  steel  is  slowly  heated  in  temper- 
ing and  the  heat  is  distributed  equally  over  the  entire  piece,  the 
molecules  assume  the  most  stable  position  with  regard  to  each 
other,  and  when  the  tool  is  in  use,  all  are  alike  affected  by  any 
shock  sustained.  The  effects  of  heat  on  copper  and  bronze  are 
exactly  opposite  to  those  manifested  by  steel,  as  when  such  metals 
are  cooled  slowly  they  become  brittle  and  hard,  but  when  cooled 
rapidly  soft  and  malleable. 

Tempering  in   Oil. 

Almost  all  large  shops  in  which  any  amount  of  hardening  and 
tempering  are  done  have  discarded  the  method  of  tempering  by 
colors  and  have  adopted  the  more  reliable  methods  of  doing  it  in 
oil,  gaging  the  heat  by  thermomenter.  A  kettle  containing  the  oil 
i^  placed  on  the  fire  and  heated  to  the  right  temperature ;  the 
hardened  parts  are  thrown  in  and  left  in  the  liquid  until  drawn. 
By  this  method  there  is  no  possibility  of  overdrawing,  as  it  is  im- 
possible for  the  parts  to  become  hotter  than  the  oil.  When  tem- 
pering in  this  manner  it  is  not  necessary  to  brighten  the  work 
before  the  operation,  and  when  a  lot  of  such  work  is  done  it  will 
be  accomplished  much  cheaper  than  if  the  old  method  were  used ; 
besides,  the  most  satisfactory  results  will  be  attained. 


I2O  HARDENING,    TEMPERING    AND    ANNEALING. 

Hardening  and  Tempering  Springs. 

As  very  often  springs  are  included  in  the  constructions  of 
fixtures,  appliances,  and  machines,  it  is  well  to  understand  how  to 
harden  and  temper  them  successfully.  For  small  and  medium- 
sized  springs  use  a  solution  composed  of  one-half  sperm  oil,  one- 
half  neat's  foot  oil  with  an  ounce  of  rosin,  and  the  springs  will 
come  out  of  the  bath  tempered  as  desired.  For  heavy  springs, 
which  have  to  exert  a  great  deal  of  pressure,  use  hot  water.  Have 
the  water  boiling  and  plunge  the  springs,  when  at  the  proper  heat, 
into  it.  By  adopting  this  method  no  burning  off  will  be  necessary, 
as  the  springs  will  be  the  proper  temper.  What  is  more,  they  will 
not  break  or  "crawl  up"  when  in  use. 

Blazing  Off  Springs. 

To  temper  springs  by  "blazing  off"  use  cottonseed  oil.  For 
some  work,  however,  a  mixture  of  this  and  fish  oil  will  work  bet- 
ter than  either  of  the  two  oils  alone.  In  doing  this  work  experi- 
ments will  determine  just  what  oil  or  what  proportion  of  a 
mixture  of  the  two  will  contribute  to  attaining  the  best  re- 
sults. 

Tempering  Rock  Drills  in  Crude  Oil. 

For  the  tempering  of  rock  drills  crude  oil  will  give  the  best  re- 
sults, and  by  using  it  as  a  quenching  bath  even  the  amateur  may 
temper  steel  to  stand  like  an  expert.  This  is  so  because  when 
using  oil  a  slight  variation  in  temperature  does  not  produce  the 
effect  on  steel  that  water  does.  The  experience  with  crude  oil 


FIG.  77. — ROCK  DRILL  STEEL. 

for  the  tempering  of  rock  drills  by  one  who  understands  the 
requirements  of  such  work  is  of  value  and  may  cause  its  more 
extensive  use.  B.  Hastings,  in  the  Mining  and  Scientific  Press, 
states : 

"It  is  a  very  rare  thing  for  an  oil-tempered  drill  to  break,  and 
it   wears   much   better   than   a   water-tempered   one.      The   most 


TEMPERING.  121 

serviceable  slack  tub  I  found  to  be  common  five-gallon  oil  can, 
with  the  top  left  as  a  flap  or  cover  to  throw  down  and  smother 
flame  in  case  the  oil  ignites  from  the  hot  steel.  If  the  vessel  is 
left  open  the  ignition,  if  it  does  occur,  is  of  little  consequence, 
like  that  of  coal  tar ;  but  with  a  partially  closed  tub  or  tank  can, 
the  accumulated  gases  are  liable  to  produce  'fireworks/  as  the 
writer  can  testify.  There  is  really  no  necessity  for  such  incon- 
venience, however,  as  the  proper  heat  for  plunging  the  steel — a 
bright  red — is  a  little  below  the  point  necessary  to  flash  the  oil. 
I  do  not  use  more  than  five  inches  of  oil  in  the  bottom  of  the 
can.  The  hotter  the  oil  becomes,  the  better  are  the  results.  The 
consumption  of  oil  is  small,  principally  due  to  that  portion 
sticking  to  the  drills  on  withdrawal.  Plunging  them  in  loose  dirt 
afterward  will  clean  them." 

Hardening  and  Tempering  Mill  Picks. 

Bath  for  Hardening. — Take  2  gallons  rain-water,  I  ounce  cor- 
rosive sublimate,  2  of  sal-ammoniac,  I  of  saltpeter,  il/2  pints  of 
rock  salt.  The  picks  should  be  heated  to  a  cherry  red,  and  cooled 
in  the  bath.  The  salt  gives  hardness,  and  the  other  ingredients 
toughness  to  the  steel ;  and  they  will  not  break,  if  they  are  left 
without  drawing  the  temper. 

Composition  for  Tempering  Cast-Steel  Mill  Picks. — To  3 
gallons  of  water  add  3  ounces  each  nitric  acid,  spirits  of  hartshorn, 
sulphate  of  zinc,  sal-ammoniac,  and  alum ;  6  ounces  salt,  with  a 
double  handful  of  hoof  parings ;  the  steel  to  be  heated  a  dark 
cherry  red.  It  must  be  kept  corked  tight  to  prevent  evapora- 
tion. 

To  Temper  Picks. — After  working  the  steel  carefully,  prepare 
a  bath  of  lead  heated  to  the  boiling  point,  which  will  be  indicated 
by  a  slight  agitation  of  the  surface.  In  it  place  the  end  of  the 
pick  to  the  depth  of  il/2  inches,  until  heated  to  the  temperature 
required.  The  principal  requisites  in  making  mill  picks  are :  First, 
get  good  steel.  Second,  work  it  at  a  low  heat ;  most  blacksmiths 
injure  steel  by  overheating.  Third,  heat  for  tempering  with- 
out direct  exposure  to  the  fire.  The  lead  bath  acts  merely  as 
a  superheater. 

Straightening  Hardened  Pieces  Which  Have  Warped. 
When  a  piece  of  steel  has  been  carefully  heated  and  just  as 
carefully  quenched,  there  is  little  chance  of  its   warping.     But 


122  HARDENING,    TEMPERING    AND    ANNEALING. 

when  a  piece  does  warp,  before  it  can  be  used  for  the  purpose 
required,  it  must  be  straightened.  To  do  this  proceed  as  follows : 
Take  two  "V"  blocks  and  place  them  on  the  bed  of  an  arbor  press 
or  a  straightening  press — either  one  will  do — and  place  the  piece 
or  tool  on  the  "V"  blocks  with  the  concave  side  down.  Then  take 
a  Bunsen  burner,  with  a  hose  attached  to  it  for  the  gas  supply, 
and  heat  the  concave  side ;  do  this  slowly,  and  do  not  heat  hot 
enough  to  draw  the  temper.  While  the  steel  is  hot  apply  sufficient 
pressure  to  spring  the  piece  or  tool  back  into  shape.  A  large 
number  of  hardened  pieces,  which  would  otherwise  prove  useless, 
may  be  saved  by  straightening  them  in  this  manner. 

Tempering  Thin  Articles. 

Articles  of  thin  material,  like  springs,  which  require  a  spring 
temper,  are  frequently  treated  by  dipping  in  oil  and  then  burning 
off  the  oil  over  the  fire.  Blacksmiths  adopted  this  method  in- 
stead of  trying  to  temper  by  watching  the  color,  as  it  is  found 
that  it  subjects  the  piece  to  just  about  enough  heat  to  produce 
the  desired  results.  In  the  case  of  thicker  pieces,  however,  like 
tools,  it  is  much  better  to  use  the  hot  iron  and  watch  the  color. 
The  temper  can  thus  be  drawn  to  just  the  point  desired,  and  the 
steel  will  be  tempered  more  uniformly  both  on  the  outside  and  in- 
side than  when  the  other  method  is  used. 

Tempering  in  the  Charcoal  Flame. 

A  great  many  mechanics  prefer  to  temper  in  a  charcoal  flame. 
To  do  this  properly  the  thickest  portion,  or  the  part  not  requiring 
any  temper,  should  be  held  in  the  flame ;  and  as  it  becomes  heated, 
the  tool  should  be  wiped  at  intervals  with  an  oily  piece  of 
waste.  The  oil  will  keep  the  temper  even  and  prevent  drawing 
more  in  one  place  than  in  another.  In  drawing  the  temper  of  any 
tool  it  should  always  be  done  slowly,  as  if  it  is  done  rapidly  the 
temper  is  apt  to  run  out  before  one  is  aware  of  it. 

Tempering  Wood  Planer  Knives. 

The  following  extract  from  an  article  contributed  to  the 
"Woodworker"  gives  a  practical  method  for  tempering  wood 
planer  knives : 

"We  have  one  batch  of  knives  that  will  not  hold  an  edge  in 
oak  unless  drawn  to  a  temperature  of  about  400  degrees,  and  as 
this  shows  a  very  indistinct  color  it  is  not  easy  to  get  without  a 


TEMPERING.  123 

thermometer.  As  these  are  6,  8,  and  lo-inch  knives,  they  cannot 
be  hardened  in  water  without  a  reasonable  certainty  of  cracking 
back  the  length  of  the  bevel  in  one  or  more  places ;  and  as  oil  will 
not  carry  off  the  heat  fast  enough  to  keep  the  body  of  the  knives 
from  drawing  the  edge,  it  promised  a  serious  problem  to  solve. 
This  was  managed  in  the  following  manner,  and  after  a  few 
trials  I  was  able  to  obtain  the  proper  degree  of  hardness  without 
drawing  for  temper  at  all. 

"Take  a  vessel  of  proper  width  to  receive  the  length  of  knife, 
put  some  water  in  the  bottom  and  pour  an  inch  of  oil  on  top. 
Heat  the  edge  of  your  knife  an  even  cherry  red  back  as  far  as 
you  wish  to  harden  it,  and  holding  it  level  thrust  the  edge  into 
the  oil  for  a  moment  until  the  color  leaves,  then  slowly  let  it  down 
into  the  water.  The  oil  cools  without  cracking,  and  the  water 
prevents  the  heat  in  the  body  from  drawing  the  edge.  It  is  not 
necessary  to  harden  all  long  knives  in  this  manner,  as  the  oil 
alone  will  produce  a  sufficient  hardness  in  ordinary  cases  if  a  large 
enough  body  of  oil  is  used  and  the  edge  of  the  knife  is  immersed 
with  a  stirring  motion.  It  can  then  be  tempered  to  about  500 
degrees  by  the  heat  of  the  body  of  the  knife  and  suddenly  cooled 
in  water  at  about  80  degrees.  These  long  knives  are  pretty  sure 
to  warp  some  when  tempering  or  hardening  in  this  way,  the  back 
or  soft  steel  side  contracting  more  than  the  face.  To  straighten, 
lay  face  down  on  an  anvil  and  with  a  round-nosed  machinist's 
hammer  give  a  quick,  sharp  blow,  distributed  evenly  between  the 
back  edge  bevel  and  the  line  of  front  end  of  slots.  Be  careful 
to  hammer  directly  over  the  spot  resting  on  anvil  or  the  knife 
will  vibrate  in  the  hand  and  the  force  of  the  blow  will  be  diffused 
and  lost.  This  gentle  hammering  stretches  the  back  of  the  knife, 
and  when  its  length  equals  the  face  it  will  be  straight." 

Tempering  Swords  and  Cutlasses. 

The  tempering  of  swords  so  that  they  will  stand  the  United 
States  government  test  may  be  accomplished  by  heating  in  a  char- 
coal fire  to  a  bright  red  and  quenching  in  pure  water,  afterward 
drawing  the  temper  in  a  charcoal  flame. 

Drawing  Polished  Steel  Articles  to  a  Straiv  Color  or  Blue. 

The  surface  of  polished  steel  articles  will  acquire  a  pale  straw 
color  at  460  degrees  F.,  and  a  uniform  deep  blue  at  580  degrees  F. 
The  other  shades  between  these  may  be  had  at  intermittent  tem- 
peratures. 


124  HARDENING,    TEMPERING   AND   ANNEALING. 

Tempering  Solutions. 

1.  Saltpeter,  sal-ammoniac  and  alum,  of  each  2  ounces;  salt, 
i]/2  pounds;  soft  water,  3  gallons.     Never  heat  over  cherry  red; 
draw   no   temper.      Sal-ammoniac   and   iron   turnings   or   filings 
make  good  rust  joints. 

2.  To  6  quarts  of  soft  water  add  i  ounce  of  corrosive  sublim- 
ate and  two  handfuls  of  common  salt.     When  dissolved  the  mix- 
ture is  ready  for  use.     The  first  gives  toughness,  the  latter  hard- 
ness to  the  steel.     Remember  this  is  deadly  poison. 

3.  Water,  3  gallons ;  salt,  2  quarts ;   sal-ammoniac  and  salt- 
peter, of  each  2  ounces ;  ashes  from  white  ash  bark,  i  shovelful 
The  ashes  cause  the  steel  to  scale  white  and  smooth  as  silver. 
Do  not  hammer  too  cold.     To  avoid  flaws  do  not  heat  too  high, 
which  opens  the  pores  of  the  steel.     If  heated  carefully  you  will 
get  hardness,  toughness  and  the  finest  quality. 

4.  Salt,   4  ounces ;   saltpeter,   y2    ounce ;   pulverized   alum,    i 
ounce  to  i  gallon  of  soft  water.     Heat  the  articles  to  a  cherry 
red,  and  quench,  but  do  not  draw  temper. 

5.  Saltpeter  and  alum,  each  2  ounces  ;  sal-ammoniac,  l/2  ounce  ; 
salt,   iy2  ounces  to  2  gallons  of  soft  water.     Heat  parts  to  be 
tempered  to  a  cherry  red  and  quench. 

Tables  of  Colors,  Melting  Points  and  Suitable  Tempers  for 

Given  Tools. 

The  following  tables  have  been  carefully  arranged  and  will 
be  found  to  be  approximately  correct : 

Melting  Points  of  Solids. 

Deg.  F. 

Aluminum    M57 

Antimony     from      8n  to  1,150 

Bismuth    from     476  to      512 

Copper    from  1,929  to  1,996 

Lead    from     608  to      618 

Mercury   —  39 

Tin     from     442  to     451 

Zinc    from      680  to      779 

Wr't" 

Cast  iron 2,477 

Gold 2,587 

Silver    1,250 

Steel    2,501 

Glass     2,377 

Brass     '. 1,897 


TEMPERING.  125 

Melting  Points  of  Solids — Continued. 

Wr't" 

Platinum    3,077 

Cadmium    602 

Saltpetre    600 

Sulphur 225 

Potassium    135 

Table  of  Tempers  to   Which  Tools  Should  be  Drawn,  Arranged 
Alphabetically. 

Tool.  Color.  Deg.  of  Tem.  F. 

A 

Augers Light    purple 530 

Axes    Dark  purple 550 

All  cutting  tools  for  soft  material Very  light  yellow 420 

All  hand  taps  and  dies Straw  yellow 460 

All  kinds  of  hand  reamers Straw  yellow 460 

All  percussion  tools  for  metal Blue    549 

B 

Bone-cutting   tools Very  pale  yellow 430 

Boring  cutters Straw  yellow 460 

Butt  mills  for  brass Very  light  yellow 420 

Burnishers     Very  light  yellow 420 

Bending  and  forming  dies Dark  yellow 490 

C 

Chasers    Straw  yellow 460 

Coppersmiths'   tools Light    purple 530 

Cold  chisels  for  steel Light  purple 530 

Cold  chisels  for  cast  iron Dark  purple 550 

Cold  chisels  for  wrought  iron Light  purple 530 

Circular  saws  for  metal Light    purple 539 

Cutting  tools  for  iron Light    yellow 440 

Collets    Dark  yellow 490 

Chuck  jaws Dark  yellow 490 

Chisel   for  wood Spotted    red-brown 510 

Clutch   bolts Very  dark  blue 601 

Cams  with  sharp  corners Very  dark  blue 601 

Clutch  springs Blue 549 

D 

Drifts    Brown    yellow 500 

Dental  and  surgical  instruments Light  purple 530 

Drawing  mandrels Very  light  yellow 420 

Drills   for   brass Straw  yellow 460 

E 

Edging  .  cutters Light  purple 530 

Embossing  dies Light    yellow 440 


126  HARDENING,    TEMPERING    AND   ANNEALING. 

Table  of  Tempers  to   Which   Tools  'Should  be  Drawn,  Arranged 
Alphabetically — Continued. 

Tool.  Color.  Deg.  of  Tern.  & 

F 

Flat  drills  for  brass Brown    yellow 500 

Flat  drills  for  steel  and  iron Straw  yellow 460 

Firmer  chisels Dark  purple 550 

Framing    chisels Dark  purple 550 

G 

Gimlets Dark  purple 550 

Gauges    Brown    yellow 500 

H 

Hammer  faces ^ Very  pale  yellow 430 

Hand  plane  irons Brown    yellow 500 

Half-round  bits Straw  yellow 460 

Hack    saws Dark  purple 550 

Hand  tools Light    yellow 440 

Hand  springs Purple    blue 529  to  53 1 

Hammers  and  drop  dies Spotted    red-brown 510 

I 

Ivory-cutting    tools Very  pale  yellow 430 

Inserted  saw  teeth Straw  yellow : 460 

J 

Jaw  pieces Purple    blue 529  to  531 

L 

Leather-cutting  dies Straw  yellow 460 

Lathe  tools   for  brass Very  light  yellow 420 

Large  cutting  dies Straw  yellow 460 

Large  forging  dies  for  press Dark  yellow 490 

M 

Moulding  and  planing  tools Dark  purple 55° 

Milling  cutters Straw  yellow 460 

Milling  cutters  for  brass Very  light  yellow 420 

N 

Needles    Dark  purple 550 

P 

Press  dies  for  brass Light  purple 53<> 

Press   dies   for   cold-rolled   stock Brown    yellow 500 

Press  dies  for  sheet  steel Straw  yellow 460 

Press   dies   for   leather Straw  yellow 460 

Press  dies  for  paper Dark   blue 570 

Penknives    Straw  yellow 460 


TEMPERING. 

Table  of  Tempers  to   Which  Tools  Should  be  Drawn,  Arranged 
A  Iphabetically — Continued. 

Tool.  Color.  Deg.  of  Tern.  F. 

Planer  tools  for  iron Straw  yellow 460 

Planer   tools    for   steel Very  pale  yellow 430 

Parts  subject  to  shock Very  dark  blue 601 

Paper    cutters Very  pale  yellow 430 

R 

Rock  drills Straw  yellow 460 

Reamers Straw  yellow 460 

S 

Shell  reamers Brown    yellow 500 

Screw-cutting  dies Straw  yellow 460 

Scrapers  for  brass Very  pale  yellow 430 

Steel-engraving    tools Very  pale  yellow 430 

Scrapers  Very    light   yellow 420 

Slight    turning   tools Very  pale  yellow .  430 

Screw    drivers Dark  purple 550 

Springs , Dark  purple 550 

Saws  for  wood Dark  blue 570 

Saws  for  bone  and  ivory Dark  purple 550 

Stone-cutting    tools Brown    yellow 500 

Small   milling  cutters Straw  yellow 460 

Shear  blades Dark  yellow 490 

Springs Very  dark  blue 601 

T 

Twist    drills Brown    yellow 500 

Taps    Straw  yellow 460 

Threading  dies  for  brass Light    yellow 440 

Truing   blocks Straw  yellow 460 

Tools  for  wood,  to  be  filed Purple    blue 529  to  531 

lools  for  wood,  not  to  be  filed Spotted  red-brown 510 

W. 

Wood-engraving    tools Very  pale  yellow 430 

Wood-boring  cutters Brown    yellow 500. 

Wire-drawing  dies Straw   yellow 460 

Table  of  Suitable  Temperatures  for —  Deg.  F. 

Annealing    steel 900  to  1,300 

Annealing  malleable  iron   (furnace  iron) 1,100  to  1,400 

Annealing  malleable  iron    (cupola  iron) 1,500  to  1,700 

Annealing  glass    (initial   temperature) 950 

Working    glass 1,200  to  1,475 

Melting  glass   (into  fluid) 2,200 

Hardening   tool    steel 1,200  to  1,400 


128  HARDENING,    TEMPERING    AND    ANNEALING. 

Table  of  Suitable  Temperatures  for —  Deg.  F. 

Casehardening  iron  and  soft  steel 1,300  to  1,500 

Core  ovens  in  foundries 350 

Drying  kilns  for  wood 300 

Baking   white    enamel 150 

Baking  red  and  green  enamel 250 

Baking  black  enamel ' 300 

Vulcanizing    rubber 295 

Table  of  Temper  Colors  of  Steel.  Deg.  F. 

Faint    yellow 430 

Straw  color  460 

Dark  straw 470 

Brown    yellow 500 

Purple     530 

Blue 550 

Full  blue   560 

Polish   blue 580 

Dark   blue 600 

Pale  blue 610 

Blue  tinged  with  green 630 

Bright  red  in  dark 725 

Red  hot  in  twilight 884 

Red  visible  by  day i ,077 


CHAPTER  VI. 

CASEHARDENING    PROCESSES THE    USE    OF    MACHINERY    STEEL    FOR 

CUTTING    TOOLS    AND    THE     TREATMENT     OF     IT. 

The  Use  of  Machine  Steel  for  Press  Tools. 
For  a  large  number  of  purposes,  particularly  in  the  line  of 
sheet  metal  working,  machinery  steel  tools,  if  properly  hardened, 
will  answer  as  well  and  sometimes  better  than  tool  steel  ones,  and 
if  the  following  process  is  used  to  harden  such  tools  they  will  be 
found  to  give  the  best  of  results  and  may  be  used  with  success  for 
cutting  the  different  metals.  In  order  that  the  parts  or  tools  may 
do  their  work  and  last  long,  they  must  be  hardened  very  deep  and 
come  out  with  a  fine  compact  grain.  For  dies  which  are  to  be 
used  for  punching  regular  shaped  blanks  from  light  soft  stock, 
machine  steel  casehardened  tools  will  give  excellent  satisfaction, 
as  they  are  far  cheaper  to  make  and  will  last  as  long  as  though 
made  of  tool  steel. 

Outfit  for  Fine  Grain  Casehardening. 

To  do  this  work  properly  the  following  outfit  is  necessary: 
A  good  hardening  oven,  a  number  of  hardening  boxes,  a  good 
supply  of  raw  bone,  granulated,  the  same  amount  of  granulated 
charcoal,  some  hydro-carbonated  bone  and  the  same  amount 
of  charred  leather.  A  tank  large  enough  to  hold  a  good  supply 
of  water,  a  small  tank  so  arranged  as  to  allow  of  heating  to  any 
desired  temperature,  and  a  bath  of  raw  linseed  oil,  and  the  outfit 
will  be  complete. 

Packing  and  Heating  the  Work. 

Pack  and  heat  the  work  as  you  would  for  regular  caseharden- 
ing,  and  leave  it  in  the  oven  to  cool.  When  perfectly  cool  heat 
the  pieces  in  hot  lead  and  quench  the  same  as  tool  steel.  If  the 
pieces  are  small  they  should  be  re-packed  in  the  hardening  box 
with  granulated  charcoal  and  heated.  When  packing  in  charcoal 
do  not  mix  with  any  kind  of  bone  or  any  other  carbonizing  mat- 
ter; such  substances  open  the  grain,  and  the  object  of  the  second 
heat  is  to  close  the  grain.  The  hardening  heat  should  be  as  low 
as  possible,  and  the  hardened  pieces  will  come  out  close  in  grain, 


I3O  HARDENING,    TEMPERING   AND    ANNEALING. 

with  a  hard,  tough  surface  all  over,  while  the  center  remains  soft 
and  the  piece  will  be  stronger  than  if  made  of  tool  steel. 

Case  hardening  Cutting  Tools. 

When  machine  steel  tools  are  to  be  used  for  cutting  they 
should  be  packed  for  the  first  heat  in  a  mixture  composed  of  equal 
parts  of  charcoal  and  charred  leather,  finely  granulated.  The  use 
of  charred  leather  gives  a  much  tougher  effect,  to  the  steel  than 
bone,  as  the  leather  is  almost  free  from  phosphorus,  while  bone  is 
not,  and  as  phosphorus  makes  steel  brittle  the  substance  which 
contains  the  least  amount  of  it  should  be  used.  Tools  which  are 
tc  be  used  for  bending  and  forming  may  be  packed  in  bone,  which 
will  carbonize  them  as  required.  When  using  either  bone  or 
leather  an  equal  amount  of  granulated  charcoal  mixed  with  it  will 
prevent  the  kernels  of  bone  and  leather  from  adhering  and  form- 
ing a  solid  mass  when  hot,  and  as  charcoal  is  an  excellent  con- 
ductor the  pieces  packed  within  the  hardening  box  will  be  heated 
quicker  than  if  no  charcoal  were  used. 

Plow  to   Caseharden,   Color  and  Anneal  with   Granulated  Raw 

Bone. 

In  order  to  attain  good  and  satisfactory  results  in  caseharden- 
ing  by  the  use  of  granulated  raw  bone,  as  well  as  to  color  and 
anneal  properly  with  it,  the  treatment  of  the  steel  must  be  in  ac- 
cordance with  the  use  to  which  it  is  subsequently  to  be  put.  In 
the  following  we  give  special  directions  for  casehardening,  color- 
ing and  annealing  machine  steel  by  the  use  of  Hubbard's  granu- 
lated raw  bone.  The  matter  was  kindly  furnished  to  the  author 
by  the  manufacturers  of  the  bone,  Rogers  &  Hubbard  Company, 
Middletown,  Conn.,  who  have  gone  to  much  trouble  and  expense 
in  order  to  discover  the  best  methods  for  casehardening,  coloring: 
and  annealing  under  different  conditions,  and  for  parts  used  for 
special  purposes. 

To  Caseharden  Without  Colors. 

Pack  the  work  to  be  hardened  in  a  cast-iron  box.  The  box 
should  be  of  suitable  size ;  use  a  box  about  4  inches  deep,  4  inches 
wide  and  8  inches  long.  Put  a  layer  of  granulated  raw  bone  in 
the  bottom,  then  a  layer  of  work  to  be  hardened,  and  so  on  until 
the  box  is  full  within  1^2  inches  of  the  top.  This  space  may  be 
filled  with  old  bone  that  has  been  used.  Put  on  the  cover  and 
lid  and  lute  with  clay.  In  packing,  be  sure  to  keep  the  work  at 


CASEHARDENING    PROCESSES.  13! 

least  one-half  an  inch  from  the  sides  and  ends  of  the  box.  Heat 
to  a  good  cherry  red  from  three  to  four  hours,  according  to  the 
depth  of  hardening  desired.  Dump  the  whole  contents  in  clear, 
cool,  soft  water.  Delicate  pieces  should  be  dumped  in  oil.  Fot; 
larger  work  use  a  larger  box  and  keep  in  longer. 

Hardening  Extra  Heavy  Work. 

To  harden  pieces  4  inches  and  upward  in  diameter  the  work 
should  be  packed  in  clear  raw  bone,  No.  I  or  No.  2,  surrounded 
by  at  least  il/2  to  2  inches  of  the  "one,"  and  heated  to  an  orange, 
or  almost  white  heat,  for  18  hours,  and  then  plunged  into  cold 
running  water,  salt  water  preferred.  If  the  piece  does  not  harden 
hard  enough  at  one  operation,  it  should  be  repacked  and  heated 
again,  the  same  as  the  first  time,  and  plunged  into  cold  water  as 
before.  Great  care  should  be  taken  in  heating  these  pieces.  After 
the  heat  is  up  to  the  required  temperature,  it  should  be  kept  so 
until  the  piece  is  ready  to  be  plunged  into  the  water. 

Hardening  Drawbridge  Disc  and  Similar  Work. 

Large  flat  pieces  require  especial  care  and  treatment.  For 
hardening  pieces  or  discs  2  feet  in  diameter  and  4  inches  thick,  put 
four  or  five  inches  No.  I  granulated  raw  bone  in  bottom  of  pack- 
ing box.  On  this  bed  lay  work  to  be  hardened  flat  side  down, 
pack  at  least  four  inches  of  granulated  raw  bone  around  the 
diameter  and  on  top.  If  you  have  any  charred  leather,  a  thin 
layer  added  next  to  the  work  may  prevent  scaling,  but  it  is  not 
a  necessity.  After  packing,  cover  the  box  with  an  iron  cover  and 
lute  with  clay.  Heat  to  a  bright  cherry  red  and  hold  at  this  heat 
for  eight  or  ten  hours.  These  large  flat  pieces  have  a  tendency 
to  warp  a  little,  but  this  can  be  reduced  to  a  minimum  by  being- 
careful  not  to  heat  above  a  good  cherry,  and  by  dipping  the  pieces 
edgewise  into  a  large  body  of  cold  water,  which  has  a  steady 
stream  running  into  it,  or  some  other  way  of  keeping  the  water 
agitated. 

In  hardening  large  flat  pieces,  there  are  four  essential  points; 
— plenty  of  bone  ;  even,  steady,  bright  cherry  heat ;  dip  edgewise ; 
large  body  of  water  that  is  kept  agitated. 

Hardening  Five-inch  Thrust  Bearing  Rings. 
If  made  from  ordinary  soft  machinery  steel  with  about  .10  per 
cent  or  .15  per  cent  of  carbon,  it  would  be  necessary  to  pack  them 


132  HARDENING,    TEMPERING    AND   ANNEALING. 

in  No.  2  granulated  raw  bone  and  heat  twelve  hours  to  a  good 
bright  cherry  red,  then  re-pack  and  heat  nine  hours  again  to  a 
good  bright  cherry  red.  Dip  in  salt  water  singly  (do  not  dump). 
We  would  advise  using  a  cast-iron  box  n  inches  long,  7  inches 
deep,  6  inches  wide,  covered  with  an  iron  cover  that  will  fit  inside. 
Lute  around  the  edge  with  clay.  Such  a  box  will  hold  ten  rings. 

To  Harden  Rods  or  Rolls,  Leaving  Tenons  Soft  for  Riveting. 

Finish  the  pieces  to  the  required  diameter,  leaving  a  little  extra 
length  for  trimming,  but  do  not  turn  the  tenons  on  the  end  or  ends. 
Pack  and  heat  the  pieces  as  usual,  but  do  not  dump.  Allow  the 
work  to  remain  in  the  boxes  until  all  heat  has  passed  off  the 
same  as  the  annealing.  On  being  taken  from  the  boxes  the  pieces 
are  thoroughly  annealed  with  the  outer  surface  carbonized  to  a 
greater  or  less  depth,  according  to  the  time  they  were  in  the 
furnace.  After  turning  the  tenon  heat  the  piece  to  a  cherry  and 
plunge  into  cold  water  the  same  as  to  harden  tool  steel.  On  re- 
moving from  the  bath  the  work  will  be  found  to  be  extremely 
hard  wherever  the  outer  surface  has  not  been  removed  since  car- 
bonizing, but  wherever  this  surface  has  been  removed,  as  in  turn- 
ing the  tenon,  the  softness  of  the  original  stock  has  been  removed. 
If  the  stock  is  required  in  rods  for  tenon,  screw  or  similar  ma- 
chines, cut  in  pieces  as  long  as  your  furnace  and  pots  will  take, 
carbonize  and  anneal  as  described  above.  The  finished  work  from 
these  rods  upon  coming  from  the  machines  is  ready  to  harden, 
leaving  such  portions  soft  as  have  been  turned  or  cut  after  car- 
bonizing. 

The  principle  of  this  method  is  that  only  carbonized  portions 
will  harden  when  heated  and  chilled  and  as  the  carbon  enters  but 
a  short  distance  the  carbonized  surface  may  readily  be  removed, 
thus  leaving  the  original  stock,  which  will  not  harden,  exposed  to 
the  action  of  the  fire  and  water.  The  principle  may  be  adapted  to 
a  great  variety  of  uses  where  hardness  and  softness  are  required 
on  the  same  piece. 

When  it  is  not  practical  to  remove  any  of  the  stock  in  order 
to  remove  the  carbonized  surface,  the  parts  desired  soft  may  be 
protected  by  covering  them  with  a  coating  of  fire-clay,  thus  pre- 
venting the  carbonizing  of  the  stock  at  these  particular  points, 
with  the  result  that  when  plunged  in  the  cold  bath  they  will  re- 
main soft. 


CASEHARDENING    PROCESSES.  133 

To   Caseharden  Malleable  Iron. 

If  malleable  iron  is  thoroughly  malleable  it  should  be  treated 
exactly  the  same  as  any  wrought  iron.  If  it  is  only  half  annealed, 
as  some  of  it  is,  then  there  are  no  directions  to  give  in  regard  to 
it.  Sometimes  it  will  take  a  light  casehardening,  sometimes  it 
will  harden  half  way  through,  other  times  all  the  way  through, 
according  to  the  condition  it  is  in.  If  it  is  thoroughly  decar- 
bonized, as  it  could  be,  then  it  is  just  about  the  same  as  a  piece 
of  iron. 

In  order  to  obtain  the  best  results  it  is'  necessary  to  employ 
a  furnace  that  gives  and  maintains  a  good  uniform  heat. 
To   Use  the  Old  Bone. 

After  dumping  the  pots,  separate  the  bone  from  the  work  and 
dry  it  thoroughly;  it  will  then  be  coal  black.  This  can  be  used 
again  by  adding  new  granulated  raw  bone,  about  one  part  new  to 
two  of  the  old.  Place  upon  your  bench  a  box  each  of  the 
granulated  raw  bone  and  the  bone  black ;  one  is  white,  the  other 
black ;  a  mixture  will  make  a  gray.  For  very  small  work,  screws, 
etc.,  use  a  dark  gray,  i.  e.,  two  or  three  parts  bone  black  and  one 
of  the  raw  bone.  For  very  large  work  use  white  or  raw  bone ; 
a  little  proportion  of  raw  bone  and  burned  bone  to  be  used  for 
different  sizes  of  work.  The  different  shades  of  gray  make  an 
easy  and  reliable  guide  after  having  once  become  familiar  with 
them. 

Pameacha  raw  bone  may  be  used  in  exactly  the  same  way. 
The  shades  of  the  color  are  not  as  true  a  guide,  however,  as  the 
pameacha  raw  bone  is  quite  dark-colored  itself. 

Constant  burning  will  finally  turn  the  bone  white;  it  is  then 
valueless  for  casehardening. 

Bone  and  Charcoal. 

The  following  is  recommended  by  a  reliable  party  as  a  prac- 
tical and  economical  method  of  using  granulated  raw  bone :  For 
ordinary  iron  work,  such  as  set  or  cap  screws,  etc.,  use  one  part 
granulated  raw  bone  to  three  parts  pulverized  charcoal,  thoroughly 
mixed;  in  this  we  pack  our  work  in  iron  pots,  then  sprinkle  a 
little  charcoal  dust  on  the  top.  In  casehardening  Bessemer  steel 
or  fine  small  drawn  work  we  diminish  the  quantity  of  bone  some- 
what. Pameacha  raw  bone  may  be  used  in  the  place  of  the 
granulated  raw  bone,  but  the  proportion  of  charcoal  should  be 
somewhat  diminished. 


134  HARDENING,    TEMPERING    AND    ANNEALING. 

Using  the  T ell-Talc. 

Parties  who  have  had  but  little  experience  in  casehardening 
may  find  the  "tell-tale"  a  help  to  them.  The  tell-tale  consists  of 
a  piece  of  round  iron,  as  near  the  size  of  the  work  to  be  hardened 
as  possible,  that  reaches  down  into  the  center  of  the  pot,  extending 
up  through  the  cover  about  high  enough  for  the  tongs.  The  hole 
in  the  cover  should  be  just  large  enough  to  allow  the  pin  or  tell- 
tale to  slip  out  readily.  When  you  think  the  work  has  been  in 
long  enough,  remove  the  tell-tale  with  the  tongs  without  dis- 
turbing the  pot,  and  plunge  it  immediately  into  cold  water.  There 
may  be  one  or  more  tell-tales  in  the  cover,  as  desired.  If  the  tell- 
tale shows  the  work  to  be  hardened  to  sufficient  depth,  dump  as 
instructed,  otherwise  leave  in  longer,  and  test  as  before. 

To  Obtain  Colors  with  Granulated  Raw  Bone. 
This  process  not  only  gives  the  finest  colors  and  mottling,  but 
it  casehardens  the  work  at  the  same  time. 

Preparation    of   the    Work. 

To  obtain  bright"  colors,  the  work  must  be  nicely  polished  and 
perfectly  clean ;  poorly  finished,  greasy  work  will  not  take  bright 
colors.  A  clean,  brightly  polished  surface  is  necessary  for  the 
finest  work. 

To  Char  the  Bone. 

To  produce  the  colors  the  granulated  raw  bone  must  be  thor- 
oughly charred.  This  can  be  easily  and  cheaply  done  by  putting 
it  into  iron  boxes  about  9  x  9  x  36  inches,  covering  tightly  and 
placing  it  in  the  furnace  at  night,  after  the  work  has  been  with- 
drawn.  The  remnant  of  fire  and  heat  of  the  retort  is  sufficient 
to  char  the  bone  during  the  night.  If,  however,  there  is  much 
fire  left,  it  must  be  partially  deadened,  as  the  object  is  to  simply 
char  the  bone  without  burning  it.  If  the  smaller  boxes  are  used, 
they  must  be  watched  and  taken  out  when  "one"  is  charred.  If 
there  is  sufficient  oven  room  this  can  be  arranged  so  as  to  be  done 
during  the  day. 

.    To  Pack  the  Work. 

Pack  the  work  in  a  cast-iron  box  of  suitable  size  for  the  work ; 
for  screws  or  similar  work  Y\  to  ^4  mcn,  use  box  4  inches  deep, 
4  inches  wide  and  8  inches  long.  Put  a  layer  of  charred  bone  in 
the  bottom,  then  a  layer  of  the  work  to  be  hardened  and  colored, 
and  so  on  until  the  box  is  filled  to  within  il/2  inches  of  the  top; 


CASEI1ARDENING  PROCESSES.  135 

fill  this  space  with  charred  bone,  put  on  the  cover  and  lute  with 
day.  In  packing,  be  sure  and  keep  the  work  at  least  y2  inch 
from  the  sides  and  ends  of  the  box,  and  do  not  let  any  two  pieces 
of  the  work  come  in  contact. 

The  Heat. 

Place  the  boxes  in  the  furnace  and  bring  to  a  cherry  red,  and 
hold  at  this  heat  two  to  four  hours.  To  get  nice  colors,  the  heat 
must  be  held  uniform ;  if  too  hot,  there  will  be  no  color.  A  good 
nice  cherry  red  must  be  maintained  from  the  time  the  boxes  are 
placed  in  the  furnace  until  they  are  ready  to  dump.  With  very 
small  work  this  time  may  be  reduced  somewhat ;  with  heavy  work 
it  may  be  increased.  A  little  practice  will  be  necessary  to  deter- 
mine this  point. 

In  order  to  obtain  the  best  results  it  is  necessary  to  employ  a 
furnace  that  gives  and  maintains  a  good  uniform  heat. 

The  Bath. 

While  good  colors  can  be  obtained  in  rather  hard  water,  yet 
soft  water  will  give  much  better  results.  The  bath  should  be 
arranged  as  follows :  Bring  your  water  pipe  up  through  the  bot- 
tom of  the  barrel  reaching  about  half  way  to  the  top ;  make  the 
outlet  about  six  inches  from  the  bottom  of  the  barrel;  into  your 
supply  pipe  connect  a  pipe  from  an  air  pump  so  that  the  air  and 
water  will  mix  in  the  pipe  and  come  into  the  barrel  together. 
When  dumping,  have  a  running  stream  of  water  and  air  floating 
into  the  barrel.  Hang  a  sieve  under  the  surface  of  the  water  in 
which  to  dump  the  work.  While  the  air  pump  is  not  absolutely 
necessary,  yet  its  use  gives  more  satisfactory  results.  Running 
water  is  necessary  if  large  lots  are  to  be  dumped,  as  the  water 
must  be  kept  cold.  Small  lots  may  be  dumped  into  the  bath  of 
still  water. 

To  Dump  the  Work. 

When  the  work  is  ready  to  dump,  draw  the  boxes  from  the 
furnace,  hold  them  close  to  the  surface  of  the  water  over  the  sieve 
and  dump,  turning  over  the  box  quickly.  This  operation  requires 
the  nicest  care,  in  order  that  the  air  may  not  strike  the  iron  before 
it  reaches  the  water.  If  the  air  strikes  the  iron,  it  assumes  a  black 
or  blue-black  streaked  color. 

Cleaning  the  Work. 
Separate  the  work  from  the  bone  and  boil  out  in  clean  water. 


136  HARDENING,    TEMPERING    AND   ANNEALING. 

Dry  in  sawdust  and  oil  over  slightly,  which  will  bring  out  the 
color  and  keep  it  from  tarnishing. 

Colors  from  a  Light  Straw  to  a  Deep  Blue. 
Caseharden  the  articles  as  instructed,  then  roll  them  in  a 
tumbling  barrel  of  some  sort,  until  they  are  brought  to  a  proper 
finish.  After  they  are  thoroughly  polished,  place  them  in  a  cylin- 
der and  tumble  them  over  a  regular  gas  blaze  until  drawn  to  a 
desired  color,  then  plunge  in  cold  water,  dry  in  sawdust  and  oil 
slightly  to  avoid  tarnishing.  By  using  a  regular  gas  blaze,  and 
noting  the  exact  time  required,  the  process  can  be  timed  exactly 
to  produce  any  color  desired  from  the  light  straw  to  a  deep  blue. 
If  preferred,  you  can  put  the  pieces  in  a  wire  cylinder  where  you 
can  see  the  color,  and  revolve  over  a  slow  fire.  The  fire  must  be 
free  from  gas  or  the  pieces  will  be  stained. 

Directions  for  Annealing  with  Granulated  Raiu  Bone. 

Pack  the  work  to  be  annealed  about  the  same  as  for  case- 
hardening,  but  it  is  not  necessary  to  keep  the  pieces  separate,  using 
the  bone  that  has  been  burned  a  number  of  times  until  it  is  almost 
white.  Place  in  the  oven  and  heat  until  it  is  heated  through  to 
a  cherry  red. 

Cooling. 

As  soon  as  the  work  has  reached  the  required  heat  stop  the 
blast,  and  if  the  oven  is  not  required  for  further  use,  let  the  boxes 
remain  in  the  furnace  and  cool  down  with  the  fire.  Upon  remov- 
ing the  boxes  from  the  oven  cover  them  with  warm  ashes,  old 
burned  bone  or  air-slacked  lime,  so  as  to  retain  the  heat  as  long 
as  possible.  Do  not  remove  the  work  from  the  boxes  until  all 
heat  has  passed  off.  The  more  gradual  the  cooling  the  better 
the  results. 

To  Anneal  Low  Carbon  S'teel  Bars. 

For  bars  6^/2  inches  in  diameter  use  Q-inch  iron  pipe  for  pack- 
ing box,  other  sizes  in  proportion.  Pack  the  steel  in  a  mixture  of 
half  charcoal  and  half  bone  that  has  been  used  once  or  twice. 
This  proportion  does  not  tend  to  recarbonize  more  than  five  (5) 
per  cent,  and  in  all  cases  it  is  sufficient  to  maintain  the  amount  of 
carbon  originally  in  the  steel.  Great  care  must  be  taken  in  heating 
steel  for  annealing,  heating  it  only  to  the  same  degree  of  heat  that 
you  would  for  casehardening,  i.  e.,  a  good  cherry  red.  Heavy  bars 
6  inches  to  7  inches  in  diameter  should  be  placed  in  the  furnace 


CASEHARDENING    PROCESSES.  137 

in  the  morning  and  left  in  until  the  next  morning,  but  no  draft 
should  be  allowed  on  during  the  night.  Upon  removing  the  box 
from  the  furnace  cover  them  with  warm  ashes,  old  burned  bone  or 
air-slacked  lime,  so  as  to  retain  the  heat  as  long  as  possible.  Do 
not  remove  the  steel  from  the  boxes  until  all  heat  has  passed  off. 

Smaller  bars  are  treated  in  exactly  the  same  way  except  the 
length  of  time  required  for  heating ;  this  diminishes  as  the  size  of 
the  bar  is  reduced. 

To  Anneal  Iron  Castings. 

To  anneal  small  or  thin  iron  castings,  pack  them  in  a  cast-iron 
pot  with  a  mixture  of  bright  cast-iron  turnings  or  filings  and 
pulverized  charcoal,  half  each ;  have  a  layer  of  the  mixture  be- 
tween the  castings ;  it  will  help  to  keep  them  from  warping  and 
heat  them  more  uniformly.  Place  the  pots  in  the  oven  and  bring 
to  a  good  bright  cherry  red,  then  let  them  cool  off.  If  it  is  neces- 
sary that  they  be  very  soft,  hold  them  at  a  bright  red  for  two  or 
three  hours. 

It  is  absolutely  necessary  that  the  castings  be  left  in  the  pots 
to  cool  off. 

In  order  to  obtain  the  best  results  it  is  necessary  to  employ  a 
furnace  that  gives  and  maintains  a  good  uniform  heat. 

Casehardening  with  Cyanide  of  Potassium. 

The  casehardening  of  machinery  steel  with  cyanide  of  potas- 
sium can  be  accomplished  in  a  number  of  different  ways.  The 
most  common  method  of  casehardening  with  cyanide  is  to  heat 
the  article  to  almost  a  white  heat  and  soak  it  into  a  cake  of  the 
cyanide,  then  reheat  and  plunge  into  water.  This  method,  how- 
ever, is  a  very  poor  one  except  for  special  jobs  or  a  few  small 
articles. 

A  highly  satisfactory  method  of  casehardening  with  cyanide 
can  be  attained  by  melting  the  cyanide  in  an  iron  pot,  and  dipping 
the  heated  articles  into  it.  To  use  this  method  for  hardening 
small  articles  a  cast-iron  pot  will  answer,  while  for  large  pieces 
or  ones  with  delicate  portions,  which  are  to  be  merely  colored,  a 
mild  steel  pot  will  be  necessary. 

In  Fig.  78  a  cheaply  made  pot  of  the  second  kind  is  shown. 
It  can  be  made  of  flat  mild  steel  from  two  pieces  of  J^-inch  to 
^-inch  thick,  which  should  be  bent  to  the  shape  shown  and  riveted 
and  welded  together.  With  a  pot  of  this  kind  soft  steel  pieces  may 
be  heated  in  the  cyanide,  and  when  dipped  properly  in  water  will 


130  HARDENING,    TEMPERING    AND   ANNEALING. 

show  up  with  colors  equally  as  clear  as  those  possible  to  attain  by 
packing  and  heating  in  bone  and  leather.  One  decided  advantage 
of  this  process,  for  certain  articles,  is  that  delicate  parts  will  not 
spring  out  of  shape,  as  no  hardness  is  produced  in  them,  which 
is  a  decided  advantage  in  a  large  variety  of  work  which  is  re- 
quired to  be  colored,  but  not  hard. 

When  the  articles  are  desired  to  be  hard  the  cast-iron  pot  may 
be  used,  although  care  will  be  necessary  in  order  to  prevent  ex- 
cessive warping  in  any  but  very  small  pieces. 


FIG.    78. — SHEET  STEEL   POT  FOR   CYANIDE   HARDENING. 

A  strange  thing  about  this  process  is  that  the  first  time  a  new 
steel  pot  is  used  the  work  heated  in  it  will  come  through  as  hard 
as  if  a  cast-iron  pot  was  used.  To  overcome  this,  heat  a  new  pot 
once  before  doing  any  work.  Where  a  great  deal  of  this  work  is 
done  a  hard  coal-burning  furnace  should  be  built  with  a  lid  of 
cast-iron  on  the  top  or  roof,  in  which  a  hole  about  the  shape  of  the 
pot  has  been  cored.  In  hardening  or  coloring  by  this  method  be 
sure  that  the  articles  are  perfectly  dry  before  putting  them  into 
the  cyanide.  If  there  is  any  moisture  or  dampness  in  the  grain 
the  cyanide  will  fly  like  hot  lead. 


CASEHARDEN1NG    PROCESSES.  139 

Accurate  Sectional  Casehardening.  . 

The  accurate  sectional  casehardening  of  special  machinery 
steel  parts  may  be  accomplished  by  a  special  process  so  that  the 
hard  and  soft  surfaces  may  be  controlled  with  absolute  accuracy. 

Take  the  article  or  part,  of  which  sections  only  are  desired  to 
be  hardened,  and  coat  the  surfaces  requiring  hardening  with  black 
Japan  enamel,  having  first  thoroughly  cleaned  the  surfaces  to  be 
afterward  enameled,  and  after  they  are  perfectly  dry  have  the 
work  plated  with  copper,  being  sure  that  the  Japan  coating  has 
not  been  eaten  away  by  any  cleaning  fluids. 

After  plating,  the  piece  must  be  carbonized,  which  ordinarily 
requires  from  three  to  four  hours  at  a  bright  red  heat  in  bone 
dust.  At  this  heat  the  pores  of  the  metal  open  and  freely  absorb 
the  carbon.  After  the  heating  period  has  expired  remove  the 
box  and  allow  the  article  to  cool  slowly  in  the  bone  dust.  When 
the  part  is  cold  remove  from  the  bone,  heat  to  a  red  in  an  open 
fire  and  quench  in  cold  water. 

The  fracture  of  a  piece  of  metal  treated  as  described  above 
will  present  a  fine  velvety  appearance,  this  being  brought  about 
through  the  second  heating.  If  the  part  is  quenched  after  the 
first  heating  or  working  process,  a  coarse  grain  will  be  the  crude 
result. 

Upon  testing  the  properly  heated  piece  with  a  file,  it  will  be 
found  that,  the  plated  surfaces  are  soft  and  the  Japanned  ones  hard. 
This  result  comes  about  through  the  copper  plating  preventing  the 
absorption  of  carbon  during  the  roasting  process  and  the  Japan 
burning  off  and  allowing  the  opposite  to  occur,  allowing  the  carbon 
to  penetrate  to  a  depth  of  1-16  inch.  By  repeating  the  process 
the  hardened  surface  will  deepen  and  the  structure  of  the  metal 
will  not  deteriorate. 

To  Produce  Fine  Grained  Hardened  Machine  Steel  Parts. 

The  reason  why  machinery  steel  has  not  been  adopted  and  used 
extensively  in  place  of  expensive  tool  steel  is  that  very  few  me- 
chanics are  able  to  harden  it  so  as  to  produce  a  fine  grain.  When 
it  is  considered  that  machine  steel  would  replace  to  advantage 
many  tool  steel  parts  if  the  process  for  producing  a  fine  grain  was 
generally  known  the  value  of  the  method  is  obvious. 

All  steel  parts  which  are  subjected  to  pressure,  wear,  or  con- 
cussion are  required  to  have  a  strong  close-grained  backing  in 


I4O  HARDENING,    TEMPERING   AND    ANNEALING. 

order  to  stand  up  well  when  in  use.  Tool  steel  has  this  fine  grain, 
while  machine  steel  in  its  natural  condition  has  not,  and  when  case- 
hardened,  by  the  ordinary  process,  the  grain  becomes  even  coarser 
through  the  pores  opening  during  the  heating  process  when  the 
carbon  is  absorbed ;  the  higher  the  heat  to  which  such  parts  are 
brought  the  coarser  the  grain. 

To  harden  machine  steel  parts  and  articles  so  as  to  produce 
a  grain  equal  to  that  of  high-grade  tool  steel  proceed  as  directed 
in  this  chapter  under  heading,  "The  Use  of  Machine  Steel  for 
Press  Tools."  The  process  will  answer  for  all  parts  and  articles 
which  can  be  made  from  mild  steel  which  will  be  subjected  to 
strain,  wear  or  pressure,  such  as  cutting  dies  for  thin  stock,  form- 
ing and  bending  dies,  cams,  plug,  ring,  and  snap  gages ;  bicycle, 
sewing  and  typewriting  machine  parts,  spindles,  and  a  variety  of 
other  parts  which  will  suggest  themselves  to  the  reader. 

Casehardening  Ends  of  Steel  Rails. 

A  process  for  casehardening  the  ends  of  track  rails,  which  or- 
dinarily are  of  comparatively  short  endurance  because  of  the 
greater  wear  to  which  they  are  subjected,  has  been  invented  by 
M.  E.  Coyan,  of  the  Carnegie  Steel  Company's  Works,  at  Home- 
stead, Pa.  The  process  obviates  loss  of  service,  now  quite  general,, 
in  having  to  remove  tracks  with  battered  ends,  while  the  inter- 
mediate portions  are  yet  sound.  The  description  of  the  process 
as  given  in  the  "Railway  Review"  is  given  below : 

In  operation  the  rails  are  passed  through  the  finishing  rolls  and 
are  sawed  off  and  placed  on  a  horizontal  table.  Located  at 
each  end  of  the  table  and  near  one  side  is  a  spray  designed  to 
deposit  a  casehardening  solution  on  the  ends  of  the  hot  rails  as 
they  enter  the  table.  The  rails  are  kept  moving  across  the  table 
the  same  as  in  usual  treatment,  the  casehardening  material  burning 
and  soaking  into  the  ends  until  the  rail  runs  in  contact  with  water 
sprays,  located  just  opposite  the  casehardening  sprays,  and  so 
constructed  as  to  extend  half  the  length  of  the  table.  The  ends 
coming  in  contact  remain  in  the  bath  until  they  reach  the  opposite 
side  of  the  table,  where  they  pass  from  out  of  the  bath  and  are 
carried  away  for  straighten  in  °-. 

Very  Deep  Casehardening. 

When  small  mild  steel  articles  are  required  to  be  hardened  very 
deep,  put  the  parts  into  a  crucible  and  add  enough  cyanide  of 


CASEHARDENING    PROCESSES.  14! 

potash  to  cover  them  when  melted.  Cover  the  crucible  and  heat 
as  required,  then  remove  parts  and  quench  into  a  cold  water  bath. 
Parts  treated  in  this  manner  will  harden  very  deep. 

To  Case  hard  en  Small  Iron  Parts. 

Put  into  an  iron  pot,  or  crucible,  I  part  prussiate  of  potash 
and  10  parts  of  common  salt,  fuse  together,  and  put  articles  in. 
Allow  the  parts  to  remain  in  the  liquid  for  30  minutes,  after  which 
quench  in  cold  water,  and  a  good  caseharden  will  result. 

To  Caseharden  with  Charcoal. 

To  caseharden  with  charcoal,  the  articles  finished,  but  not  pol- 
ished, should  be  put  into  an  iron  pot,  and  covered  with  an  animal 
or  vegetable  charcoal,  and  brought  to  a  red  heat,  when  they  will 
cement.  The  heat  should  be  kept  up  for  a  period  varying  with  the 
size  and  description  of  the  articles  worked  upon. 

Moxon's  Method  of  Casehardening. 

Cow's  horn  or  hoof  is  to  be  baked  or  thoroughly  dried  and 
pulverized  in  order  that  more  may  be  packed  in  the  box  with  the 
articles  to  be  worked  upon.  Bones  reduced  to  dust  will  answer  the 
same  purpose.  To  this  add  an  equal  quantity  of  bay  salt ;  mix 
then  with  this  stale  chamber-lye,  cover  the  iron  with  this  mixture, 
and  bed  it  in  the  same  as  loam,  or  inclose  it  in  an  iron  box.  Lay 
it  on  the  hearth  to  dry  and  harden,  and  then  put  into  the  fire.  Heat 
the  mass  until  a  blood  red  heat — no  higher — appears,  and  then 
remove  the  iron  and  quench  in  cold  water. 

A  Casehardening  Mixture  for  Iron. 

A  good  Casehardening  mixture  for  iron  is  composed  of  equal 
parts  prussiate  of  potash,  sal-ammoniac  and  saltpeter;  add  4^ 
ounces  more  of  sal-ammoniac  and  7  gallons  of  water.  Heat  the 
iron  red  hot  and  soak  it  in  the  composition. 

A  Casehardening  Paste. 

To  caseharden  iron  parts  quickly  and  satisfactorily,  make  a 
paste  with  a  concentrated  solution  of  loam  and  prussiate  of  potash. 
Coat  the  parts  to  be  hardened  with  the  paste  and  heat  them  to  a 
bright  red,  after  which  allow  them  to  cool  to  a  dull  red  and  then 
quench  in  a  cold  water  bath. 


142  HARDENING,    TEMPERING    AND    ANNEALING. 

Case  hardening  Polished  Parts. 

To  caseharden  mild  steel  or  iron  parts  which  have  been  pre- 
viously finished  and  polished,  heat  them  to  a  bright  red  in  a  closed 
fire  and  wipe  them  with  prussiate  of  potash.  When  the  prussiate 
appears  to  decompose  and  dissipate,  quench  the  article  or  part  in 
cold  water.  When  the  process  has  been  conducted  properly  the 
surface  of  the  parts  will  be  well  hardened  to  a  depth  sufficient  to 
resist  a  file.  This  process  will  be  found  to  be  a  great  improve- 
ment over  the  ordinary  method  as  the  application  of  the  prussiate 
allows  of  casehardening  a  part,  or  a  number  of  parts,  of  the  ar- 
ticles and  still  leave  the  remaining  sections  soft. 

Casehardening  as  it  Should  be  Understood. 

In  order  to  caseharden  successfully  it  is  not  merely  necessary 
to  follow  the  directions  herein  given.  The  principles  must  be  un- 
derstood and  retained  in  order  that  the  operation  shall  be  accom- 
plished in  a  manner  fitting  special  requirements.  In  the  first  place 
the  operation  of  casehardening  consists  first  and  foremost  of  giving 
a  surface  to  steel  or  iron  that  will  be  capable  of  receiving  a  great 
external  hardness,  while  the  interior  remains  soft  and  in  its  natural 
tough  state.  Thus  the  part  will  be  capable  of  withstanding  wear, 
strain  and  concussion  when  in  use.  Second,  the  above  mentioned 
results  can  only  be  accomplished  satisfactorily  by  packing  and  heat- 
ing the  parts  in  close  vessels  filled  with  animal  carbon. 

The  following  being  kept  in  mind,  no  difficulty  will  be  experi- 
enced in  performing  casehardening  operations  successfully :  Pack 
in  a  good  animal  carbon,  make  the  box  air-tight  by  luting  with 
clay,  place  in  fire  and  keep  at  a  red  heat  for  a  length  of  time  suffi- 
cient to  allow  of  hardening  to  the  depth  desired — a  half  hour  of 
heat  will  allow  of  hardening  1-32  inch  deep,  an  hour  1-16  inch, 
two  hours  l/&  inch,  and  so  forth,  the  longer  the  heating  period  the 
greater  the  depth  to  which  the  pieces  will  be  hardened.  After  the 
heating  period  has  elapsed  the  parts  may  be  taken  from  the  box 
and  quenched  in  cold  water,  or  better  still,  they  may  be  reheated 
to  a  cherry  red  and  then  quenched.  When  cool,  remove  from  the 
water  and  dry  thoroughly,  to  prevent  rusting,  by  riddling  them  in 
a  sieve  with  dry  sawdust.  To  keep  delicate  articles  from  blistering 
during  the  heating  process,  dip  them  into  a  powder  of  burnt  bones, 
leather,  or  some  other  coaly  animal  matter. 


CHAPTER  VII. 

HARDENING  AND  TEMPERING  MILLING  CUTTERS  AND  SIMILAR  TOOLS, 

Hardening  Milling  Cutters  in  the  Open  Fire. 

For  the  hardening  of  milling  cutters  and  tools  of  a  similar  na- 
ture, water  or  brine  is  mostly  used,  the  liquid  being  kept  in  a  tank 
with  an  exhaust  pipe  and  a  supply  pipe  connected  with  it.  Solu- 
tions are  used  to  some  extent  and  good  results  are  obtained.  On 
the  whole,  however,  success  in  hardening  such  tools  depends  prin- 
cipally upon  the  man  who  does  the  heating  and  quenching. 

To  harden  a  milling  machine  cutter  in  the  open  fire,  have  a 
large,  high  charcoal  fire  and  bury  the  cutter  well  in  it  and  use  only 
enough  blast  to  heat  the  work  to  the  required  temperature,  being* 
careful  to  get  the  heat  uniform  throughout.  If  the  cutter  has  not 
been  annealed  after  roughing  and  drilling  the  hole  through  it,  re- 
move it  from  the  fire  when  red  hot  and  allow  it  to  cool  off  slowly 
until  a  black  appears.  It  can  then  be  again  placed  in  the  fire, 
slowly  brought  to  the  required  heat,  plunged  into  the  bath  of  tepid 
water  or  brine  and  worked  around  well  until  it  stops  "singing." 
At  this  point  it  should  be  removed  and  instantly  plunged  in  the  oil 
bath  and  left  there  until  it  is  cool,  when  the  strain  should  be  re- 
moved by  holding  over  the  fire  until  it  is  warm  enough  to  snap 
when  touched  by  a  drop  of  water.  It  can  then  be  laid  aside  and 
the  temper  drawn  at  leisure.  In  hardening  punch  press  dies  they 
can  be  treated  the  same ;  if  there  are  any  screw  holes  for  stripper 
or  guide  screws  they  should  be  filled  with  fire  clay,  graphite  or 
asbestos.  Much  depends  on  an  even,  uniform  heat ;  uneven  heat 
causes  more  cutters  and  dies  to  crack  than  high  heat.  Steel  should 
never  be  given  any  more  heat  than  is  necessary  for  the  operation 
desired. 

Hardening  Large  Milling  Cutters. 

Large,  plain  or  former  milling  cutters,  say  over  $]/2  inches  in 
diameter  and  4  inches  long,  to  harden  should  be  packed  in  a  mix- 
ture of  equal  quantities  of  granulated  charred  leather  and  charcoal, 
taking  care  not  to  have  any  part  of  the  mill  within,  say,  2  inches  of 
the  box  at  any  point.  Keep  it  in  the  furnace  for  4  to  4^2  hours 
after  the  box  is  heated  through  to  a  low  red ;  remove  the  box  from 


144 


HARDENING,    TEMPERING   AND   ANNEALING. 


HARDENING    MILLING    CUTTERS. 


145 


FIG.  80. — TYPES   OF   MILLING   CUTTERS. 


146 


HARDENING,    TEMPERING    AND    ANNEALING. 


the  furnace  at  the  expiration  of  the  time  and  quench  the  cutter  in 
a  bath  of  raw  linseed  oil,  twirling  it  around  rapidly  in  the  oil  so  as 


FIG.  8l. — SPECIAL  FORM- 
ING  CUTTER. 


FIG.  82. — DOUBLE   FACE 
MILL. 


to  cause  the  oil  to  come  in  contact  with  the  teeth.  Allow  the 
cutter  to  remain  in  the  oil  until  cold.  A  formed  mill  with  heavy 
teeth  does  not  need  to  have  the  temper  drawn.  Mills  with 


FIG.  83.— GANG  OF  STRAIGHT-FACED   MILLING   CUTTERS. 

teeth  cut  in  the  ordinary  manner  should  be  run  quite  as  long,  and 
may  be  drawn  for  ordinary  work  to  a  light  straw  color,  or  if  drawn 


HARDENING    MILLING    CUTTERS.  147 

In  a  kettle  gaging  the  heat  by  a  thermometer  to  425  or  430  degrees 
Fahr. 

We  have  seen  a  large  number  of  milling  cutters  and  similar 
tools  treated  by  this  method  and  have  never  known  one  to  be  lost 
by  cracking.  In  years  of  experience  with  this  method  we  have  had 
but  a  few  pieces  crack. 

Hardening  and  Tempering  Milling  Cutters  in  Water  and  Oil. 

A  rapid  and  highly  satisfactory  method  for  hardening  and 
tempering  milling  cutters  is  by  the  combined  oil  and  water  method. 


FIG.  84. — GANG  OF  MILLING   CUTTERS  FOR  MACHINING  A 
WIDE-FORMED  SURFACE. 

When  only  a  small  quantity  of  such  tools  are  required,  this  method 
will  be  found  superior  to  the  ordinary  hardening  and  tempering 
method. 

The  method  is  as  follows ;    The  cutter  to  be  hardened  is  heated 


FIG.  85. — FORMED   FACE   MILL. 


FIG.  86. — SHELL  END  MILL. 


to  a  proper  uniform  temperature,  quenched  into  a  cold-water  bath 
and  left  there  long  enough  to  harden  the  outside  only,  but  not 
enough  to  cool  the  steel  clear  through.  It  is  then  taken  from  the 
water  as  quickly  as  possible  and  plunged  into  lard  oil  and  held 


148  HARDENING,    TEMPERING   AND    ANNEALING. 

there  until  the  outside  is  almost  cold.  The  tool  is  then  taken  from 
the  oil  and  the  ' 'temper7'  immediately  drawn  by  allowing  the  heat 
remaining  in  the  core  of  the  tool  to  draw  the  teeth;  this  may  be 
aided  to  some  extent  by  holding  the  tool  in  the  flame  of  the  forge 
or  furnace.  The  reheating  should  be  continued  until  the  oil  com- 
mences to  smoke.  To  insure  an  even  temper  it  is  best  to  then 


FIG.   87.  — GANG   OF   CUTTERS. 

plunge  the  tool  for  an  instant  into  the  oil  and  again  heat,  doing 
this  several  times  until  the  smoke  rises  evenly  from  all  over  the 
tool.  This  second  plunge  into  the  oil  tends  to  cool  off  any  fine 
points  that  might  become  overheated,  while  the  tool  is  not  left  in 
the  oil  long  enough  to  cool  off  the  thicker  parts,  thus  insuring  a 
more  uniform  and  evener  heat  than  would  be  the  case  if  the  tool 
were  heated  all  at  once. 

Advantages  of  the  Method. 
The  above-described  method  may  seem  to  some  to  be  a  more 


FIG.  88. — SPECIAL  MILLING   CUTTER. 

tedious  one  than  that  ordinarily  used,  but  as  the  time  saved  is  con- 
siderable, and  the  results,  particularly  in  experienced  hands,  are 
much  more  reliable,  it  should  be  adopted  where  good  milling  cut- 
ters are  required. 

The  ordinary  method  of  tempering  tool-steel  milling  cutters  is 


HARDENING    MILLING    CUTTERS. 


149 


to  heat  the  cutter  to  the  proper  temperature  and  then  cool  it  "dead 
cold"  in  water,  brine,  or  solution.  When  cold  it  is  removed  from 
the  bath  and  the  teeth  are  polished.  Then  the  cutter  is  "drawn" 
to  the  proper  color  by  heating  from  some  external  means,  such  as 
over  a  red-hot  piece  of  iron  or  a  low  fire,  or  in  oil  or  sand  bath. 

The  polishing  for  tempering  takes  considerable  time,  as  it  must 
be  pretty  well  done  in  order  to  allow  the  temper  colors  to  show  up 


FIG. 


. — SPECIAL  END  MILL. 


FIG.  90. — TAPER   MILL. 


properly.  Then,  again,  the  steel  is  "dead  cold"  and  will  require 
considerable  heat  to  raise  it  to  the  proper  temperature  to  give  the 
desired  temper.  All  the  heat  that  goes  into  the  steel  must  go 
through  the  cutting  edges,  leaving  them  as  soft  as,  if  not  softer, 
than  the  body  of  the  tool,  when  they  should  be  the  hardest  part  of 
the  tool.  By  the  other  methods  the  results  are  different,  as  the 


FIG.  91. — FORMED    BUTT   MILL. 

teeth,  or  cutting  edges,  which  are,  of  course,  the  parts  that  are 
wanted  hard,  are  hard ;  while  the  central  part  or  core  of  the  tool 
is  comparatively  soft,  which  is  in  all  cases  a  desirable  condition. 

When  milling  cutters  are  hardened  in  water  they  often  crack, 
cracking  taking  place  not,  as  might  be  imagined,  when  the  hot 
steel  is  first  plunged  into  the  water,  but  about  that  time  the  central 
part  is  becoming  real  cold,  as  the  outside  cutting  edges  are  properly 


150 


HARDENING,    TEMPERING    AND   ANNEALING. 


hardened  while  the  inside  is  yet  comparatively  hot ;  and  when  the 
inside  cools  and  contracts  while  the  outside  remains  rigid,  the 
cracking-  takes  place.  The  slower  the  tool  is  cooled,  the  longer  the 
time  in  which  the  central  metal  has  a  chance  to  "adjust"  itself  to 
molecular  changes,  and  consequently  there  is  less  liability  of  crack- 


FIG.  92. — FORMED   BUTT   MIU,. 


ing.     For  this  reason  hardening  in  oil  is  not  as  liable  to  crack 
tools,  but  for  the  same  reason  the  tools  are  not  as  hard. 

By  the  oil  and  water  method  the  outside  is  hardened  in  water 
and  the  inside  in  oil,  thus  giving  the  cutting  edges  the  required 
hardness  and  at  the  same  time  lessening  the  tendency  of  cracking 
or  warping  by  more  slowly  cooling  the  inside. 


FIG.  94. — ANGLE   END   Mil,!,. 


FIG.  95. — FORMED   BUTT   Mil,!,. 


A  good  way  to  decide  upon  the  proper  instant  at  which  to  draw 
the  tool  from  the  water,  when  hardening  the  outside,  is  to  put  the 
hand  in  the  water  near  the  tool,  and  as  soon  as  the  water  ceases  to 
boil  on  the  surface  of  the  steel,  the  tool  should  be  removed  from 
the  water  and  plunged  into  the  oil  bath. 


HARDENING    MILLING    CUTTERS.  15! 

The  object  of  this  cooling  first  in  water  and  then  in  oil  is  this : 
The  outside  of  the  tool  is  wanted  very  hard ;  the  inside  somewhat 
softer.  The  faster  the  heat  is  abstracted  from  the  heated  tool,  the 
harder  it  becomes ;  so  by  first  plunging  it  into  the  water  the  cutting 
edges  are  given  the  desired  degree  of  hardness,  and  as  soon  as 
they  are  hardened,  the  tool,  with  the  central  part  still  hot,  is 


FIG.  96. — SPECIAL,  FORMED  BUTT  MILL.  FIG.  97. — END  MILLS. 

plunged  into  oil ;  and  as  the  oil  does  not  abstract  the  heat  as  fast 
as  the  water,  the  steel  has  more  time  to  adjust  itself  to  molecular 
motion  and  there  is  less  tendency  to  crack.  Again,  the  oil  left 
on  the  outside  of  the  tool  serves  as  an  indicator  for  determining 
the  temperature  at  which  to  reheat  the  steel  to  give  the  proper 
temper.  As  the  tool  is  not  completely  cooled  in  the  oil,  very  little 


.  98. — SPECIAL  MILL. 

external  heat  is  required  to  draw  it.  In  fact,  the  drawing  of  the 
temper  really  begins  immediately  upon  removing  the  tool  from 
the  water  bath. 

Lard  oil  is  the  best  to  use  in  tempering  in  this  way,  and  it  has 
been  found  that  the  oil  commences  to  show  a  very  faint  smoke  at 
about  the  same  temperature  as  a  light  straw ;  the  proper  temper 
may  be  considered  as  reached  when  the  smoke  is  seen  coming 
from  all  parts  of  the  tool. 


152 


HARDENING,    TEMPERING    AND    ANNEALING. 


Tools  tempered  in  this  way  will  prove  to  be  harder  and  yet 
tougher  than  those  tempered  according  to  the  ordinary  method. 
Milling  cutters  from  y\  inch  in  diameter  up  have  been  tempered 


FIG.    99. — SPECIAL 


FIG.   100. — ANGULAR   END   MILL. 

in  this  way,  as  well  as  taps  of  various  kinds  and  sizes ;  reamers 
and  other  like  tools  so  tempered  have  always  been  very  satis- 
factory. 

Hardening    V-Shapcd  Milling   Cutters. 
The  following  directions  for  hardening  V-shaped  milling  cut- 


FIG.   101. — DOUBLE   SLOTTING   END    MILL. 


FIG.    102. — END   MILL. 


FIG.   103. — FACING 
MILL. 


ters  for  milling  tool  steel  if  followed  out  will  be  the  means  of  se- 
curing satisfactory  results. 


HARDENING    MILLING    CUTTERS. 


153 


Heat  the  cutters  in  a  gas  furnace,  open  fire  or  in  a  hot  lead 
bath.  Not  so  much  depends  on  the  means  used  for  heating  as 
upon  how  hot  and  whether  uniformly  heated ;  and  as  to  lead  stick- 
ing to  the  work,  if  it  is  used,  there  should  be  little  trouble  if  pure 
lead  is  used  with  plenty  of  broken  charcoal  on  top  to  prevent 
oxidation ;  but  if  there  is  still  trouble  it  can  be  avoided  by  coating 
the  article  with  salt  before  putting  into  the  lead-heating  bath. 
This  is  easily  done  by  warming  the  work  up  to  a  blue  and  dipping 
in  a  strong  solution  of  salt  and  water. 

In  hardening,  the  cutters  may  be  cooled  in  cold  water  or  brine, 
temperature  depending  on  the  character  of  cutter,  whether  very 


FIG.   104. — HOLLOW    MILLS. 


;  delicate  or  not.  With  some 'heavy  cutters  it  might  be  ice  cold, 
while  in  the  case  of  very  thin,  delicate  cutters  it  would  be  better 
to  have  the  bath  up  to  blood  heat  or  even  higher ;  it  is  simply  a 
•question  of  preventing  cracking. 

Remove  the  cutters  from  the  cooling  bath  as  soon  as  the  teeth 
have  cooled  sufficiently  to  harden,  and  instantly  immerse  them  in 
oil  to  remain  there,  if  convenient,  until  cold. 

How  to  Harden  Hollow  Mills. 

When  hollow  mills  are  to  be  hardened,  care  should  be  taken 
when  heating  not  to  heat  very  much  above  the  teeth,  as  it  is  not 
necessary  for  the  back  to  be  hard.  When  the  proper  heat  has 
<been  attained,  the  mill  should  be  inverted  and  hardened  in  the 


154 


HARDENING,    TEMPERING   AND   ANNEALING. 


bath  with  the  teeth  up,  and  it  should  be  worked  up  and  down 
rapidly  in  the  bath  in  order  to  force  the  contents  into  the  hole. 
Better  results  are  always  attained  if  this  method  of  dipping  is 
adopted  with  pieces  having  holes  running  part  way  through  them, 
as  then  the  steam  can  escape  and  the  water  can  enter  the  hole ; 
whereas,  if  dipped  with  the  opening  down,  steam  which  generates 
rises  in  the  hole,  and  as  there  is  more  steam  than  the  hole  can  con- 
tain, it  escapes  from  the  bottom  and  blows  the  water  from  the 
teeth,  not  allowing  them  to  harden  properly.  Vapors  generated 
in  the  bath  are  a  source  of  annoyance  often  overlooked  by  inex- 
perienced hardeners,  and  often  cause  a  great  deal  of  trouble. 

Milling  Glitters. 

Milling  cutters  may  be  classified  in  four  distinct  types.  The 
first  and  probably  the  most  common  form  is  known  as  the  axial, 
Fig.  105,  in  which  the  surface  cut  is  parallel  to  the  axis  of  the 
cutter.  This  cutter  has  teeth  on  its  periphery  only ;  these  may  be 


IG.   105. — AXIAL  TYPE 
OF  MILLING  CUTTER. 


Badia! 

FIG.   1 06. — RADIAL  TYPE  OF 
MILLING  CUTTER. 


straight  or  spiral  teeth.  Cutters  of  this  character,  made  in  ap- 
propriate widths,  are  used  very  much  for  milling  broad,  flat  sur- 
faces and  for  cutting  keyways  in  shafts.  For  deep  cuts,  or  for 
slitting  metal,  they  are  made  of  large  diameter  and  thin.  These 
are  called  metal-slitting  saws,  and  are  ground  hollow  on  the  sides 
for  clearance. 

The  second  class  of  cutters  is  known  as  the  radial,  Fig.  106,  in 
which  the  surface  cut  is  perpendicular  to  the  axis  of  the  cutter. 
These  cutters  are  called  radial  because  their  teeth  are  used  in  a 
plane  parallel  to  the  radii  of  the  cutter.  End  mills,  face  mills, 
butt  cutters,  etc.,  are  all  tools  in  this  class. 

The  third  class  of  cutters  is  the  angular,  Fig.  107,  in  which  the 
surface  cut  is  neither  parallel  nor  perpendicular  to  the  axis  of  the 


HARDENING    MILLING    CUTTERS. 


155 


cutter,  but  is  at  some  angle  with  this  axis.  Frequently  cutters  are 
made  with  two  different  angular  cutting  edges,  in  which  case  the 
angle  is  marked  on  each  side. 

The  fourth  class  of  cutters  is  the  formed  cutter,  as  shown  in 


PIG.   107. — ANGULAR  TYPE  OF 
MILLING  CUTTER. 


Form 

FIG.   1O8. — FORMED  TYPE  OF 
MILLING   CUTTER. 


Fig.  1 08.  The  cutting  edge  of  this  class  is  of  an  irregular  outline. 
When  properly  backed  off,  these  cutters  can  be  ground  and  retain 
their  original  form.  Gear  cutters,  tools  for  grooving  taps,  etc., 
are  all  classed  as  form  cutters. 

Among  the  numerous  engravings  in  this  book  will  be  found 


FIG.  109. — CUTTER  FOR  SPIRAL  MILLS.       INCLUSIVE  ANGLE  B  IS  52°  ; 
40°   ON   ONE   SIDE,    12°    ON   OTHER. 

illustrations  of  a  large  number  of  cutters  which  are  used  on  mill- 
ing machines.  In  most  cases  it  is  advisable  to  use  a  cutter  of 
small  diameter  rather  than  of  large  diameter.  Cutters  from  il/> 
to  2  inches  in  diameter  are  the  most  economical  for  general 
milling. 


CHAPTER  VIII. 

HARDENING,    TEMPERING   AND    STRAIGHTENING   ALL    KINDS   OF 
SMALL   TOOLS. 

Hardening  Ring  Gages. 

To  harden  ring  gages  and  other  tools  of  a  similar  nature  so 
that  they  will  harden  around  the  hole  and  leave  the  remaining 
parts  soft,  clamp  the  tool  between  flange-ended  tubes  and  allow 


FIG.  IIO. — U.  S.  STANDARD  THREAD  GAGES,  EXTERNAL 
AND  INTERNAL. 

a  stream  of  water  or  brine  to  circulate  through  them.  By  this 
method  the  walls  will  harden  out  as  far  as  the  inner  edges  of  the 
clamping  flanges. 

Dipping  Small  Tools  When  Hardening. 

When  small  tools  such  as  penknife  blades,  razor,  lancet,  chisel, 
gage-bit,  place  spoke  sheaves,  three  and  four  square  files,  round 
and  flat  files,  iron-shaving  knives  are  to  be  hardened  great  care 
must  be  taken  to  dip  them  into  the  quenching  bath  endwise  or 
perpendicularly.  By  doing  this  they  will  come  out  straight, 
while,  on  the  contrary,  if  they  are  slanted  while  dipping,  there 
will  be  a  tendency  to  warp. 


HARDEN,    TEMPER   AND    STRAIGHTEN    SMALL   TOOLS.  157 

Dipping  Half -Round  Reamers  When  Hardening. 

When  hardening  half-round  reamers  or  any  other  tools  that 
are  solid  and  half-round,  enter  them  at  an  angle  of  about  twenty 
degrees  with  the  surface  of  the  bath.  This  will  tend  to  keep  them 
straight.  In  a  half-round  tool  there  is  once  and  a  half  as  much 
surface  in  the  half-round  portion  to  be  hardened  as  on  the  flat 
side,  and  as  in  hardening  the  contraction  of  the  steel  is  equal, 
according  to  the  surface,  it  is  necessary  to  dip  the  half-round 
side  at  the  angle  mentioned.  As  the  half-round  portion  has  a 
greater  percentage  of  contraction  than  the  flat  side,  the  unequal 
contraction  will  draw  the  reamer  to  one  side  and  warp  it. 

Dipping  Fluted  Reamers  When  Hardening. 

When  hardening  fluted  reamers,  dip  them  perpendicularly  to 
a  short  distance  beyond  the  fluting,  that  is  to  say,  about  half  an 
inch,  and  withdraw  and  return  them  a  number  of  times.  This 
will  harden  all  the  lips,  and  prevent  them  from  cracking  off  at 


FIG.    III. — COUNTERSINK.  FIG.    112. — SMALL  ANGLE   MILL. 

the  water's  edge,  which  is  usually  the  case  when  a  piece  of  steel 
is  dipped  into  a  certain  depth  and  allowed  to  cool  without  moving. 
A  number  of  different  tools  are  often  broken  off  at  the  ends  in  this 
way,  without  anyone  knowing  what  caused  them  to  crack. 

Straightening   Tools  Which  Have   Warped  in  Hardening. 

When  a  piece  of  steel  which  has  been  hardened  and  tempered 
is  found  to  have  sprung,  it  may  be  straightened  as  follows :  Heat 
it  slightly,  not  enough  to  draw  the  temper,  and  it  may  be  straight- 
ened on  the  anvil  with  a  hammer.  This  cannot  be  done  when  the 
piece  is  dead  cold.  It  is  best,  however,  to  straighten  a  piece  when- 
ever possible  between  the  centers  of  a  lathe,  or  on  a  block  of  wood 
with  a  mallet.  Warm,  the  steel  will  yield  readily  to  the  blows  of 
the  mallet,  but  cold,  it  will  break  like  glass. 

A  sword  blade  which  has  warped  in  hardening  may  be  ham- 
mered flat ;  too  much  hammering,  however,  will  cause  the  blade 
to  lose  its  elasticity.  When  this  occurs  it  may  be  returned  to  its 
elastic  state  again  without  re-hardening  by  heating  slowly  to  a 


158 


HARDENING,    TEMPERING    AND   ANNEALING. 


spring  temper.     This  method  may  be  adopted  to  advantage  for 
other  kinds  of  work  also. 

Hardening  Very  Thin  Tools  so  as  to  Prevent  Warping. 

A  good  way  to  harden  very  thin  tools  so  as  to  insure  against 
their  warping  is  to  heat  them  carefully  and  stick  them  into  a  raw 
potato.  Then  remove  and  temper  as  desired  over  a  gas  flame. 

Warping  of  Long  Tools  in  Hardening. 

Trouble  with  the  warping  or  the  twisting  of  long  tools,  such 
as  taps  and  reamers,  in  hardening  and  tempering,  can  be  avoided 


FIG.    113. — INSERTED   CUTTER  PIPE  TAP. 

if  care  is  taken.  If,  in  hardening,  one  can  so  manage  as  to  retain 
a  soft  center  in  the  article  there  will  be,  or  need  be,  but  little 
difficulty  in  overcoming  the  warp.  This  will  at  least  be  found 
true  in  large  tools  which  have  a  larger  proportion  of  soft  core  than 
those  of  smaller  cross-section.  With  these  last,  and  in  fact,  in 
all,  care  must  be  taken  to  lower  the  tool  perfectly  square  into  the 
quenching  bath,  so  that  the  heat  will  be  absorbed  equally  from  all 
sides.  This  desirable  tendency  will  be  increased  if  the  tool  is 
lowered  in  the  center  of  the  bath. 

If  the  above  is  true  about  the  hardening  bath,  it  is  equally 


HARDEN,    TEMPER    AND    STRAIGHTEN    SMALL   TOOLS.  159 

so  of  the  heating  bath,  where  melted  lead  or  other  liquids  are  used 
for  heating.  One  thing  must  be  remembered,  and  that  is  that 
there  will  be  no  use  in  taking  the  trouble  to  cool  a  tool  equally  if 
it  has  been  heated  unequally.  For  this  reason,  tools  should  be 
immersed  squarely  and  centrally  into  the  heating-bath,  and  turned 
around.  The  turning  process  will  also  contribute  to  good  results 
in  quenching. 

Temperature  ((T  ell-Tales"  for  Use  in  Heating  Steel. 

In  order  to  show  just  how  hot  steel  is  that  is  being  annealed 
in  a  muffle  or  box,  supply  some  one-fourth  inch  rods,  which  may  be 
pulled  out  from  time  to  time  to  test  the  temperature. 

Working  Steel  for  Tools. 

In  forging  steel  for  tools  great  care  must  be  taken  to  hammer 
all  sides  alike.  The  careless  and  unequal  hammering  of  steel 
when  forging  is  responsible  for  a  great  deal  of  bad  work  in  hard- 
ening. Another  thing,  steel,  when  being  forged,  should  be  heated 
as  hot  as  it  will  stand  until  finishing,  and  should  then  be  ham- 
mered until  almost  black-hot.  This  treatment  will  set  the  grain 
of  the  steel  finer,  and  give  a  tool  a  better  edge  when  finished.  The 
reason  for  heating  the  steel  to  a  bright  red  heat  while  forging  is 
simply  because  it  makes  the  steel  tougher  when  hardened  and 
softer  when  annealed ;  while,  on  the  contrary,  when  steel  is  worked 
at  a  low  red  heat,  the  continued  shocks  of  the  hammer  will  so 
harden  it  as  to  make  it  almost  impossible  to  anneal  it,  and  at  the 
same  time  render  it  too  brittle,  when  hardened,  for  general  use. 

Hardening  Small  Saivs. 

To  harden  small  saws  such  as  are  used  for  screw  head  slotting, 
etc.,  heat  on  a  flat  surface  and  clamp  between  two  thick  cast-iron 
plates,  which  should  be  perfectly  level  and  coated  with  a  heavy 
grease. 

Hardening  Cutter-Bits. 

Cutter-bits  such  as  are  used  in  lathe  tool  holders  should  be 
hardened  regularly  when  soft  at  the  lower  ends.  When  too  soft 
to  use  they  should  be  laid  aside  until  a  sufficient  number  of  them 
are  at  hand  to  be  hardened.  They  can  then  be  heated  by  putting 
them  into  a  box  and  heating  them  to  a  dull  red,  and  the  end  of 
each  stuck  into  a  perforated  iron  pan,  the  bottom  of  which  should 


l6o  HARDENING,,    TEMPERING   AND   ANNEALING. 

be  covered  with  just  a  sufficient  depth  of  water  to  harden  them 
up  as  far  as  desired.  The  tools  may  then  be  ground  and  put  with 
the  new  cutters.  Do  not  let  high-grade  steel  such  as  should  be 
.used  for  cutter-bits  get  into  the  smith's  fire. 

Hardening  Mixture  for  General  Smith  Work. 

Salt,  2  ounces;  copperas,  il/2  ounces;  sal-ammoniac,  1^2 
ounces;  saltpeter,  il/2  ounces;  sal-soda,  il/2  ounces,  and  black 
oxide  magnesia,  8  ounces.  The  last  two  ingredients  should  be 
added  after  the  others  are  mixed  together.  Before  mixing  the 
ingredients,  pulverize  them  separately,  and  then  mix  well  and  dry 
before  using.  Use  like  yellow  prussiate  of  potash  and  plunge  in 
water. 

Tempering  Flat  Drills  for  Hard  Stock. 

Procure  good  high  degree  steel  and  heat  to  a  cherry  red,  and 
hammer  until  nearly  cold,  forming  the  end  into  the  requisite 
flattened  shape,  then  heat  it  again  to  a  cherry  red,  and  plunge  it 
into  a  lump  of  resin  or  into  quicksilver.  A  solution  of  cyanide 
of  potassium  in  rain  water  is  sometimes  used  for  the  tempering 
plunge-bath,  but  it  will  not  give  the  result  that  quicksilver  or  resin 
will. 

To  Temper  Gravers. 

Gravers  may  be  tempered  in  the  same  way  as  drills ;  or  the 
red-hot  tool  may  be  pressed  into  a  piece  of  lead  in  which  a  hole 
about  half  an  inch  deep  has  been  cut  to  receive  the  graver;  the 
lead  melting  around  the  article  will  give  it  an  excellent  temper. 

To  Temper  Old  Files. 

Grind  out  the  cuttings  on  one  side  of  the  file  until  a  bright 
surface  is  obtained ;  then  moisten  the  surface  with  a  little  oil, 
and  place  the  file  on  a  piece  of  red-hot  plate  with  the  bright  side 
upward.  In  about  a  minute  the  bright  surface  will  begin  to  turn 
yellow,  and  when  the  yellow  has  deepened  to  about  the  color  of 
straw,  plunge  in  cold  water. 

Hardening  and   Tempering  Small  Taps,   Knives,  Springs,  Etc. 

Secure  a  piece  of  pipe  of  sufficient  diameter  and  length  to  ac- 
commodate the  piece,  and  heat  one  end,  flatten  together  on  the 
anvil,  and  weld  so  it  will  not  leak.  Fill  the  pipe  with  lead  and 
set  it  up  in  the  fire.  When  the  lead  has  melted,  immerse  the  tool 


HARDEN,    TEMPER   AND   STRAIGHTEN    SMALL   TOOLS.  l6l 

and  let  it  remain  until  the  lead  is  red-hot.  Then  quench  in  a 
salt  water  bath  and  when  cool  remove  it.  To  temper  the  tool,  heat 
a  large  piece  of  iron  in  the  forge  to  a  red  heat.  Grease  the  tool 
all  over  with  tallow.  Remove  the  iron  from  the  forge  and  lay  on 
the  anvil.  Hold  the  tool  over  hot  iron  by  means  of  tongs  or 
pliers,  turning  it  all  the  time  until  the  desired  color  is  obtained 
and  then  drop  it  into  linseed  oil.  A  good  and  uniform  temper 
should  result. 

Tempering  Small  Spiral  Springs. 

To  temper  small  spiral  springs  heat  to  a  cherry  red  in  a  char- 
coal fire,  and  harden  in  oil.  To  temper,  blaze  off  the  oil  three 
times ;  the  same  as  for  small  flat  springs. 

To  Draw  Small  Steel  Parts  to  a  Blue. 

Fill  a  cast-iron  box  with  sand  and  heat  it  red  hot.  Then  put 
the  article,  which  has  been  first  highly  polished,  into  the  sand  and 
when  the  right  color  appears  remove  and  quench  in  oil. 

Small  steel  parts  of  guns,  typewriters,  sewing  machines,  etc., 
may  be  blued  cheaply  and  well  in  a  solution  of  ten  parts  saltpeter 
and  black  oxide  of  manganese,  heated  in  an  iron  pot  to  the  point 
where  sawdust  thrown  on  it  will  flash. 

Small  pieces  may  be  strung  on  wires  in  considerable  quanti- 
ties and  dipped  in  solution,  a  minute  or  two  being  sufficient  time 
ordinarily,  although  of  course  this  will  vary  with  the  thickness  of 
the  pieces.  The  blue  produced  by  this  process  is  what  is  called 
Government  Blue  and  is  not  quite  equal  to  the  English  Blue,  which 
is  secured  with  hot  charcoal  and  whiting,  as  all  gunmakers  will 
understand,  but  it  will  answer  very  well  and  is  very  much  cheaper. 

If  springs  are  to  be  blued,  they  may  be  hardened  and  polished 
and  the  bluing  process  will  draw  them  to  the  proper  temper  at 
the  same  time,  and  the  temper  will  be  very  uniform. 

It  will  be  well  to  bore  some  holes  in  the  solution  before  plac- 
ing on  the  fire  to  heat,  for  if  a  vent  is  not  provided  there  will  be 
a  commotion. 


CHAPTER   IX. 

THE     HARDENING    AND    TEMPERING    OF    DIES    AND    ALL    KINDS    OF 
PRESS  TOOLS   FOR  THE   WORKING  OF  SHEET    METAL. 

The  Hardening  and  Tempering  of  Press  Tools. 

Of  the  hardening  and  tempering  of  dies  and  all  manner  of 
press  tools  too  much  cannot  be  written,  as  upon  the  results  of 
this  part  of  their  construction  depends  the  efficiency  of  the  tools. 
For  heating  dies  a  gas  furnace  is  preferable,  but  when  this  is  not 
at  hand  a  good  clean  charcoal  fire  will  do. 

For  hardening  large  dies  it  is  indispensable  to  have  a  large 
tank  which  should  be  arranged  in  such  a  manner  as  to  insure  the 
rapid  cooling  of  the  steel.  A  tank  of  this  kind  can  be  arranged 
by  fixing  two  or  three  rods  across  the  inside  about  12  inches 
below  the  surface  of  the  water,  and  a  pipe  let  into  the  tank  in 
such  a  manner  as  to  allow  of  a  circulation  of  a  stream  of  water 


FIG.     114. — COMBINATION   DIES,    WITH   HARDENED   AND   GROUND   TOOL 
STEEL  WORKING  PARTS  SOLID-EORGED  TO  WROUGHT-IRON  PLATES. 

from  the  bottom  upward.  When  the  die  is  to  be  quenched  the 
water  should  be  turned  on  and  kept  running  until  the  steel  has 
cooled.  When  a  good  circulation  of  water  is  kept  up  in  the  tank 
there  will  not  be  any  soft  spots  in  the  die  after  hardening. 

It  is  often  necessary  to  construct  dies  from  forgings  of 
wrought  iron  and  tool  steel,  and,  as  the  dies  when  finished  are 
required  to  be  hardened,  it  is  necessary  there  should  be  a  good 
weld  between  the  two  parts.  To  accomplish  this  result,  when 
welding  mix  mild  steel  chips,  from  which  all  of  the  oil  has  been 


THE    HARDENING    AND   TEMPERING   OF   DIES. 


i63 


removed,  with  the  borax  and  there  will  be  no  difficulty  in  produc- 
ing a  clean  weld  and  one  which  will  not  buckle  or  separate  in 
hardening. 

Hard  or  Soft  Punches  and  Dies. 

At  times,  when  tools  are  required  for  sheet-metal  working, 
it  is  hard  to  determine  whether  a  punch  and  die  should  be  hard- 
ened, or  whether  one  of  them  should  be  left  soft,  and  if  so, 
which  one?  The  stock  to  be  worked  and  the  nature  of  the  work 
have  to  be  considered  when  deciding  this  matter.  Some  classes  of 
work  will  be  accomplished  in  the  best  manner  by  using  a  soft 
punch  and  a  hard  die ;  others  when  a  hard  punch  and  a  soft  die  are 


FIG.  115.  —  "  PUSH  -THROUGH  " 
CUTTING  AND  DRAWING 
DIE. 


FIG.   Il6. — SOLID   BOTTOM   CUTTING 
AND   DRAWING  DIE. 


used,  while  in  a  majority  of  cases  the  best  results  will  be  obtained 
by  using  a  punch  and  die  that  are  both  hard.  For  punching  or 
shearing  heavy  metals  both  die  and  punch  should  be  hard,  while 
for  all  metals  which  are  soft  and  not  over  1-16  inch  thick,  a  soft 
punch  and  a  hard  die  will  be  found  to  work  well.  By  leaving 
one  of  the  dies  soft  it  will  be  easy  to  produce  clean  blanks  during 
the  life  of  the  tools,  as  when  the  punch  and  die  become  dull  it 
will  only  be  necessary  to  grind  the  hard  one,  upset  the  soft  one 
and  shear  it  into  the  die. 

Hardening  and  Tempering  Drop.  Dies. 

If  there  is  one  class  of  tools  the  hardening  of  which  is  less  gen- 
erally understood  than  others,  it  is  the  class  used  for  drop  press 
work.  When  dies  of  this  class  are  to  be  hardened  special  care 
Is  necessary.  Instead  of  plunging  the  whole  die  into  the  quench- 


164  HARDENING,    TEMPERING   AND   ANNEALING. 

ing  bath  (when  heated  properly)  set  it  in  an  inclined  position 
and  direct  a  strong  stream  of  cold  water  onto  the  face  of  the  die. 
By  having  the  stream  strong  the  whole  die  face  will  be  covered, 
and  the  contraction  of  the  metal  at  the  surface  will  be  equal. 
Allow  the  water  to  strike  the  die  until  the  bath  ceases  to  boil, 
and  then  gradually  diminish  the  stream  and  allow  the  die  to  cool 
slowly.  By  placing  the  die  in  the  inclined  position  when  hard- 
ening, the  water  will  run  off  the  face  and  thereby  the  bottom  will 
remain  soft  and  hot  while  the  die  portion  proper  will  be  hard, 
which  is  always  a  desirable  condition  in  dies  of  this  kind.  At 
the  same  time  the  temper  can  be  drawn  by  the  heat  remaining  in 
the  base  of  the  die.  When  the  colors  appear  turn  the  water  on 
until  cool. 

When  a  muffle  is  used  to  heat  steel  parts  for  hardening,  pro- 
vide a  number  of  3-1 6-inch  rods.     Put  them  in  with  the  steel 


Redrawing  Punch.  Inside  Blank  Holder.  Redrawing  Die. 

FIG.   117. — REDRAWING  DIE  WITH   INSIDE   BLANK   HOLDER. 

and  remove  one  from  time  to  time  during  the  heating  process 
to  test  the  temperature. 

To  anneal  white  or  hard  iron  die  parts  so  that  they  may  be 
machined  with  ease,  put  the  parts  into  an  iron  box  and  pack 
around  them  a  mixture  composed  of  equal  parts  of  common 
sand,  fine  steel  turnings  and  steel  scale  from  the  rolling  mills. 
Wet  the  mixture  with  the  solution  of  sal-ammoniac,  after  which 
place  the  box  in  a  furnace  and  heat  to  a  white  heat.  Keep  the 
heat  for  five  or  six  hours,  and  then  allow  the  box  to  cool  slowly. 
When  cool  remove  the  castings  and  they  will  be  found  to  be 
malleable  enough  to  allow  of  cutting  them.  The  packing  of  the 
mixture  mentioned  above  and  the  wetting  of  it  with  the  solution 
contributes  to  the  annealing,  and  allows  of  the  castings  or  parts 
coming  through  the  process  free  from  scale  and  lumps. 

Hoiv  to  Harden  Large  Ring  Dies. 
To  harden  large  ring  dies,  which  are  to  be  ground  after  hard- 


THE    HARDENING   AND   TEMPERING   OF   DIES.  165 

ening,  and  which  are  required  to  be  very  hard  about  the  center 
of  the  hole  and  the  walls,  they  should  be  heated  in  large  iron 
boxes  as  follows :  Put  a  layer  of  fine  powdered  charcoal  about 
2  inches  deep  in  the  bottom  of  the  box  and  place  the  die  on  it. 
Fill  the  die  and  then  cover  it  to  a  depth  of  about  ^4  inch  with  a 
mixture  of  4  parts  powdered  charcoal  to  I  part  of  charred  leather, 
then  put  a  loose  cover  on  the  box  and  place  in  the  furnace. 
After  heating  about  three  hours  or  more,  according  to  the  size  of 
the  die,  the  metal  will  be  at  a  red  heat.  It  should  then  be  allowed 
to  remain  at  a  low  heat  for  about  an  hour,  which  will  insure  its 
heating  uniformly  throughout.  The  heat  should  then  be  in- 
creased until  the  die  comes  to  a  full  red  heat ;  it  is  then  ready  to 
be  quenched. 

Remove  the  box  from  the  furnace,  and  with  two  pair  of  tongs, 
and  a  man  at  opposite  sides,  if  the  die  is  too  large  for  one  man 
to  handle,  draw  the  die  from  the  box,  clean,  and  quench  squarely 


Drawing  Punch.        Blank  Holder  and  Die. 

Cutting  Punch. 

PIG.   Il8. — DOUJBLE- ACTION   CUTTING   AND   DRAWING   DIE. 

into  the  water,  working  up  and  down  until  the  red  has  entirely 
disappeared,  then  let  it  lie  still  until  cool.  When  cool  remove 
the  die  from  the  water  and  heat,  to  remove  the  strain  and  chill 
of  hardening,  until  drops  of  water  sprinkled  on  it  will  steam. 
Then  lay  it  aside  in  an  even  temperature  where  it  will  cool  off 
slowly. 

When  large  ring  dies  are  hardened  in  the  manner  described 
above  there  need  be  no  fear  that  they  will  warp,  crack  or  shrink 
excessively  or  unevenly. 

Hardening  a  Long  Punch  so  as  to  Prevent  Warping. 
Often,   after  carefully   hardening   a   long  punch,   it   will   be 


l66  HARDENING,    TEMPERING   AND   ANNEALING. 

found  to  have  warped  during  the  process — often  to  such  an  ex- 
tent as  to  make  it  useless.  There  is  a  way  by  which  this  tend- 
ency of  the  steel  may  be  eliminated  altogether — at  least  the  warp 
will  be  so  little  as  to  not  affect  the  working  qualities  of  the  tool. 
To  eliminate  the  possibility  of  warping  lower  the  steel,  when  at 
the  proper  heat,  squarely  into  the  tub,  lowering  it  as  far  as  pos- 
sible in  the  center  of  the  water.  When  this  is  done  the  heat  will 
be  absorbed  equally  from  all  sides  and  the  tendency  to  warp 
excessively  will  have  been  overcome. 

Steel  for  Small  Punches. 

When  small  punches  are  required  to  punch  heavy  stock  or 
to  operate  at  high  speeds,  never  use  drill  rod  or  Stubs  steel,  for 
the  reason  that  such  steel  is  of  the  finest  high  carbon  variety  and 
will  crystallize  rapidly  under  concussion.  In  place  of  such  ma- 
terial use  one  of  the  low  grades  of  steel;  one  which  in  order  to 
harden  it  will  be  necessary  to  heat  to  white  heat,  and  the  punches 
will  last  much  longer  than  if  made  from  the  best  grades  of  steel. 

For  small  punches  which  are  required  to  pierce  thin,  soft 
stock,  or  to  operate  at  a  slow  speed,  get  the  best  grades  of  steel 
procurable,  as  for  such  uses  the  finer  the  grade  the  better  results 
which  will  be  obtained. 

Hardening  a  Blanking  Die. 

In  order  to  harden  a  blanking  die  properly  great  care  should 
be  taken ;  first  in  the  heating  of  the  steel,  and  second  in  the 


Drawing  Punch.  Blank  Holder.  Die. 

FIG.    119. — WASH-BASIN   DRAWING   DIE.. 

quenching1.  In  all  shops  where  dies  or  other  tools  which  require 
hardening  are  constructed,  a  gas  furnace  or  "muffle"  should  be 
used  for  heating,  but  when  a  "muffle"  is  not  handy  charcoal 
should  be  used.  After  a  good  clean  fire  has  been  built,  all  screw 
and  dowel  holes  in  the  die  should  be  plugged  with  fire  clay  or 
asbestos.  By  taking  these  precautions  the  tendency  of  the  steel 
to  crack  around  the  holes  is,  as  far  as  possible,  eliminated.  We 


THE    HARDENING   AND   TEMPERING   OF   DIES.  l6/ 

now  heat  the  die  to  an  even  cherry  red,  so  that  the  entire  plate 
will  be  the  same  temperature;  then  remove  it  from  the  fire  and 
dip  it  endwise  into  the  water  (which  should  first  be  warmed 
slightly  to  take  the  chill  out),  being  careful  to  dip  down  straight, 
and  not  to  move  it  or  shake  it  around  as  that  would  increase  the 
possibility  of  the  die  warping,  or  shrinking  excessively.  After 
removing  the  die  from  the  water  it  should  be  immediately 
warmed.  Now  grind  the  face  of  the  die;  heat  a  thick  piece  of 
cast-iron  red  hot,  and  place  the  die  upon  it ;  it  can  then  be  drawn 
evenly  to  any  temper  desired.  By  taking  a  piece  of  oil  waste 
and  wiping  the  face  of  the  die  as  it  is  heating,  the  different  colors 
will  show  up  clear.  When  the  color  denoting  the  temper  re- 
quired appears,  remove  the  die  and  allow  it  to  cool  off  slowly. 

Cracks  in  Dies — Their  Cause. 

When  a  piece  of  tool  steel  in  itself  of  no  great  commercial 
value  is  worked  out  and  finished  into  an  intricate  die  the  labor 
cost  amounting  to  a  large  sum,  the  steel  is,  of  course,  very  valu- 
able; and  if  cracks  show  after  the  hardening  process,  or  the  die 
is  spoiled,  it  means  a  great  loss  to  the  establishment. 

Now  in  the  first  place,  although  we  are  apt  to  usually  con- 
found cracks  with  hardening,  very  often  the  trouble  can  be 
traced  to  the  preceding  operations  of  annealing,  forging  and 
finishing.  Of  course  there  is  a  large  number  of  dies  -spoiled 
through  carelessness  or  inexperience  in  hardening,  but  still  we 
believe  there  is  as  great  an  amount  spoiled  through  imperfect 
preceding  operations  or  through  the  operator  not  being  familiar 
with  the  nature  of  the  steel. 

A  die  may  be  carefully  heated  to  give  the  proper  temperature 
throughout,  and  may  be  quenched  in  the  bath  in  the  most  ap- 
proved manner,  but  if  it  is  not  "slightly  warmed"  after  removing 
it  from  the  hardening  bath,  it  is  liable  to  crack.  This  reheating- 
may  be  done  in  a  number  of  ways.  The  best  way  is  to  hold  the 
die  over  the  fire  until  it  is  heated  to  a  temperature  sufficient  to 
cause  a  few  drops  of  water  to  steam  when  sprinkled  on  it.  The 
heat  will  not  be  sufficient  to  make  any  of  the  temper  colors 
appear. 

The  author  has  been  connected  with  one  establishment  where 
thousands  of  dies  were  made  every  year,  and  every  die  was  re- 
heated after  hardening,  in  the  following  manner:  A  large  tank 
provided  with  a  perforated  tray  with  means  for  raising  and  lower- 


l68  HARDENING,    TEMPERING    AND    ANNEALING. 

ing  it  was  used.  The  tank  was  filled  with  water  to  within  two 
inches  of  the  top  and  a  steam  pipe  was  connected  with  it.  Then 
the  water  was  kept  at  the  boiling  point,  and  the  die  directly  after 
hardening  was  placed  upon  the  tray  which  was  then  lowered 
into  the  bath. 

We  have  known  dies  to  crack  while  being  in  the  forge  when 
the  blaze  touched  the  die  portion  proper.  This  being  brought 
about  by  a  sudden  heat  and  then  a  cold  blast  of  air  causing  the 
steel  to  expand  and  then  suddenly  contract  again,  at  a  certain 
point,  and  as  the  consequent  expansion  and  contraction  in  the 
die  does  not  extend  over  the  entire  surface,  the  charge  was  local 
and  cracks  resulted. 

A  die  made  from  a  blank  cut  from  a  bar  and  machined  and 
worked  out  without  annealing  is  liable  to  crack  when  subjected 
to  the  hardening  process,  particularly  if  the  blank  is  for  a  blank- 
ing die  of  odd  shape,  as  shown  in  Fig.  120.  If  annealed  bar  steel 
is  used  the  necessity  of  reannealing  is  also  imperative  as  the  first 
annealing  does  not  eliminate  the  liability  of  cracking. 

When  it  is  not  possible  to  anneal  the  die  blank  before  finish- 
ing to  size,  the  next  best  thing  to  do  is  to  heat  the  die  uniformly 
throughout  to  a  red  heat,  then  remove  it  from  the  fire  and  allow 
it  to  cool  until  black.  It  may  then  be  reheated  to  the  proper 
temperature  and  hardened.  In  a  forming  die  the  bulky  portion 
has  a  tendency  to  contract  away  from  the  small  portions,  which 
being  frail,  harden  first  and  do  not  alter  their  shape,  while  the 
bulky  portion  continues  to  contract  unevenly,  after  the  thin  por- 
tion becomes  ridged,  and  cracks  are  apt  to  appear  when  the  tool 
is  removed  from  the  quenching.  By  heating  the  die  to  a  high 
or  red  heat  and  then  allowing  it  to  cool  to  a  black  before  the 
hardening  heat  this  uneven  contraction  is  to  a  certain  extent  pro- 
vided for. 

In  hardening  a  die  the  quenching  of  it  so  that  the  frailest  por- 
tion enters  the  bath  first  and  hardens  before  the  thickest  por- 
tion, will  most  invariably  cause  cracks  to  appear,  as  unequal  con- 
traction takes  place  and  the  heavy  portion  contracting  the  most, 
changes  shape  in  attempting  to  draw  with  it  the  frailer  portions. 
Another  cause  of  cracks  in  dies  is  the  use  of  improper  means 
for  grinding.  When  a  die  is  ground  on  a  machine  on  which 
no  provision  is  made  for  water  cooling,  or  where  a  fine  wheel  is 
used,  cracks  often  result,  coming  about  through  the  steel  being 
unevenly  heated  during  the  grinding.  Thus,  by  using  a  coarse 


THE    HARDENING    AND    TEMPERING    OF   DIES.  ItX) 

wheel  with  a  free  water  supply  this  disagreeable  possibility  will 
be  eliminated. 

Hardening  the  Walls  of  a  Round  Die. 

Often,  in  die  work,  it  is  desired  that  the  walls  of  a  drawing 
die,  for  instance,  or  some  other  part,   such  as  the  inside  of  a 


FIG.   I2O. — BLANKING   DIE. 


hollow  punch,  should  be  hard  and  the  remaining  portion  of  the 
piece  soft.  This  may  be  accomplished  by  proceeding  as  follows : 
Clamp  the  die  or  punch,  as  the  case  may  be,  between  flanges  on 


170 


HARDENING,    TEMPERING    AND    ANNEALING. 


the  ends  of  tubes,  being  sure  to  have  the  steel  at  the  proper  heat. 
Then  allow  a  stream  of  cold  water  or  brine  to  circulate  through 
the  tube  and  the  metal  will  harden  in  depth  as  far  as  the  inside 
edges  of  the  flanges  while  the  remaining  portion  will  remain  soft. 

Reannealmg  a  Punch  or  Die  Blank. 
Sometimes  a  piece  of  steel,  which  is  to  be  used  for  a  punch 


FIG.   121. — PUNCHES   FOR   PERFORATING   HEAVY   STOCK. 


THE    HARDENING   AND    TEMPERING   OF   DIES. 


171 


or  die,  upon  starting  to  machine  it,  proves  hard,  although  it  has 
been  annealed.  When  this  is  the  case,  never  try  to  finish  it  before 
reannealing  it;  instead,  rough  it  down,  clean  out  the  centers,  if 
there  are  to  be  any,  and  anneal  it  over  again.  The  time  re- 
quired to  reanneal  the  piece  of  steel  will  be  more  than  made  up 
in  the  machining  of  it. 

Warping  of  Long  Punches  in  Hardening. 
Often  after  carefully  hardening  a  long  punch  it  will  be  found 
to  have  warped  during  the  process,  often  to  such  a  degree  as  to 
make  it  useless.  There  is  a  way  to  avoid  this  altogether,  or  at 
least  the  warp  will  be  so  slight  as  to  not  affect  the  efficiency  of 
the  tool.  To  insure  against  warping,  plunge  the  steel,  when  at 
the  proper  heat,  squarely  into  the  bath,  lowering  as  far  as  pos- 
sible into  the  center  of  the  liquid.  When  this  is  done  the  heat 
will  be  absorbed  equally  from  all  sides  and  the  tendency  to  warp 
excessively  will  have  been  eliminated. 

Hardening  Very  Small  Punches. 

When  a  large  number  of  very  small  piercing  punches  are  to 
be  hardened  they  should  be  packed  in  closed  iron  boxes  and  the 
box  heated.  When  all  the  parts  have  reached  the  proper  heat 
they  should  be  entered  into  a  bath  of  either  oil  or  water,  as  the 
nature  of  the  work  may  require,  through  a  funnel.  This  will  in- 
sure the  entering  of  the  parts  vertically  and  prevent  warping. 
Another  way  by  which  small  punches  may  be  heated  uniform  is 
by  means  of  the  lead  bath.  Keep  the  lead  at  the  proper  heat  and 
cover  the  top  with  powdered  charcoal  and  coke. 

Tempering    Small   Punches. 

Almost  all  lar^e  die  shops  in  which  any  amount  of  hardening 
and  tempering  are  clone  have  discarded  the  method  of  tempering 
by  colors,  and  have  adopted  the  more  reliable  method  of  doing  it 
in  oil,  gaging  the  heat  by  thermometer.  A  kettle  containing 
the  oil  is  placed  on  the  fire  and  heated  to  the  right  temperature 
for  the  degree  of  temper  desired  in  the  work.  The  hardened 
parts  are  then  thrown  into  the  liquid  until  drawn.  By  this 
method  there  is  no  possibility  of  overdrawing,  as  it  is  impossible 
for  the  parts  to  become  hotter  than  the  oil.  When  tempering 
punches  in  this  manner  it  is  not  necessary  to  brighten  them  be- 
fore the  operation,  and  where  a  lot  of  such  work  is  done,  it  will 


172  HARDENING,    TEMPERING    AND   ANNEALING. 

be  accomplished  much  cheaper  than  if  the  old  method  were  used ; 
besides  the  most  satisfactory  results  will  be  attained. 

Hardening  Fluids  for  Dies. 

We  have  heard  a  great  deal  about  hardening  fluids,  for  which 
it  is  claimed  dies  can  be  hardened  better  than  in  water  or  in  brine. 
Such  fluids  are  composed  chiefly  of  acids  and  will  rot  the  steel, 
and  we  should  advise  keeping  away  from  them,  as  where  it  is 
not  possible  to  harden  die  steel  in  clear  water  or  strong  brine, 
the  steel  is  useless  and  should  be  dispensed  with.  When  quench- 
ing the  heated  steel  dip  down  straight  and  don't  shake  it  about, 
but  after  keeping  it  stationary  for  a  few  seconds,  move  it  around 
slowly,  keeping  it  vertical  all  the  time.  When  the  die  or  punch 
is  of  an  intricate  shape,  about  three  inches  of  oil  on  the  top  of 
the  water  will  toughen  it  and  contribute  to  helping  the  steel 
retain  its  shape  while  hardening,  and  prevent  it  from  warping  or 
cracking  during  the  process.  Lastly,  immediately  after  harden- 
ing and  before  grinding,  the  steel  should  be  placed  on  the  fire 
and  slightly  warmed,  to  take  the  chill  and  contraction  strain  out 
and  not  laid  aside  for  a  while,  as  we  have  seen  dies  that  were  laid 
aside  after  hardening  (that  were  intact)  after  a  few  hours,  show 
cracks. 

Hardening  Thick  Round  Dies. 

Often  round  dies,  which  are  very  thick  in  proportion  to 
their  diameter,  contract  excessively  in  the  center  during  the 
hardening  process,  often  to  such  a  degree  as  to  make  them  unfit 
for  use.  To  overcome  this  tendency  have  an  arrangement  by 
which  a  stream  of  water  may  be  forced  through  the  hole  without 
wetting  the  outside ;  allowing  the  water  to  only  come  in  contact 
with  the  inside  of  the  die.  By  doing  this  the  walls  of  the  die  will 
be  hard  while  the  outside  will  remain  soft,  as  when  the  temper 
is  drawn  the  hole  will  remain  straight  and  true.  In  shops  where 
grinding  facilities  are  not  at  hand  this  method  will  work  ex- 
cellently. If  possible  use  strong  brine  for  the  hardening  fluid. 

Hardening   Poor  Die   Steel 

Quite  frequently  in  making  dies  we  run  across  a  piece  of  steel 
which  after  working  will  not  respond  satisfactorily  to  the  usual 
hardening  process.  When  this  occurs  prepare  a  solution  com- 
posed of  two  handfuls  of  common  salt  and  one  ounce  of  corrosive 
sublimate. to  about  six  quarts  of  water  and  when  the  steel  has 


THE    HARDENING    AND   TEMPERING   OF   DIES. 


173 


reached  a  good  red  heat  plunge  into  the  bath.  The  corrosive 
sublimate  gives  toughness  to  the  steel  and  the  salt  hardens.  This 
solution  is  deadly  poison ;  exercise  care  in  using  it. 

Tempering  a  Combination  Cutting  and  Drawing  Punch. 

After  the  face  of  the  punch  has  been  slightly  sheared,  and 
the  edges  of  the  drawing  die  slightly  rounded  and  highly  pol- 
ished, the  punch  is  hardened  and  then  drawn  by  laying  it  alter- 
nately on  each  of  its  four  sides  on  a  hot  plate,  tempering  the 
cutting  edges  to  a  dark  blue  and  leaving  the  inside  or  drawing 
die  portion  as  hard  as  possible.  When  finishing  the  blanking 
portion  of  the  punch,  care  has  to  be  taken  to  do  it  so  that  the 
drawing  portion  will  be  perfectly  central. 

Hardening  and  Tempering  a  Split  Gang  Punch. 
The  best  way  to  harden  and  temper  a  split  gang  punch  is  by 
the  following  method :  It  should  first  be  heated  and  hardened  in 
clear  oil,  dipping  it  from  the  back,  and  thus  preventing — as  far 
as  possible — the  legs  from  crawling  in  toward  each  other  because 
of  the  channel  between  them.  By  dipping  from  the  back  this 
will  be  overcome,  as  by  the  time  the  cutting  face  is  immersed 
the  back  will  be  hard  and  set.  It  should  then  be  polished  and 
tempered  by  drawing  from  the  back  to  a  dark  blue  to  within  }/\ 
inch  of  the  cutting  faces  and  quenched  when  those  portions  are  a 
dark  straw  color. 

Hardening  and  Tempering  Large  "Blanking"  or  "Cutting"  Dies. 

Large  "blanking"  or  "cutting"  dies  of  the  type  shown  in 
Figs.  122  to  127  require  considerable  skill  and  experience  to 
harden  and  temper  correctly.  They  should  be  carefully  heated 
and  then  quenched  into  a  large  tank  of  water  and  when  cold 
warmed  on  the  fire  to  take  the  chill  and  strain  out. 

Cutting  dies  consist  of  an  upper  "male"  die  or  "punch,"  and 
the  lower,  or  "female"  die.  They  may  be  made  in  almost  any 
size  and  shape  for  cutting  out  flat  blanks  in  tin,  iron,  steel,  alumi- 
nium, brass,  copper,  zinc,  silver,  paper,  leather,  cloth,  etc.  Ordi- 
narily, the  lower  die  is  hardened  and  tempered  to  a  degree  best 
suited  for  the  work,  while  the  punch  is  left  comparatively  soft, 
so  that  it  can  be  "hammered"  up  when  worn.  Sometimes,  as  in 
the  case  of  playing-card  dies,  it  is  preferable  to  reverse  this  and 
make  the  punch  hard,  leaving  the  die  soft.  Circumstances  de- 


174 


HARDENING,    TEMPERING   AND    ANNEALING. 


termine  whether  any  or  how  much  "shear"  should  be  given  to  the 
cutting  edge.  For  ordinary  work  in  tin,  brass,  etc.,  a  moderate 
amount  of  shear  is  desirable.  These  dies  require  to  be  made  with 
the  utmost  care,  of  materials  specially  adapted  for  the  purpose, 
and  by  experienced  and  skillful  workmen.  Ordinarily,  the  steel 
cutting  rings  are  welded  to  wrought-iron  plates,  after  which  they 


FIG.  125.— 


FIG.  127. — DIE. 


are  hardened,  carefully  tempered  and  ground  on  special  machin- 
ery. In  some  cases  it  is  preferable  to  fasten  the  steel  dies  in 
cast-iron  chucks  or  die-beds  by  means  of  keys  or  screws.  This 
applies  more  particularly  to  small  dies.  For  cutting  thick  iron, 
steel,  brass,  and  other  heavy  metals  both  the  die  and  punch  should 
be  hard  and  provided  with  strippers. 


CHAPTER  X. 

FORGING    AND    WELDING TO    ACCOMPLISH    SATISFACTORY    RESULTS 

IN    THE    FORGING   OF   STEEL   AND    IRON DROP    FORGING. 

Welding  Heats. 

In  the  welding  of  steel  to  steer  or  steel  to  iron  without  injur- 
ing the  quality  of  the  material,  the  process  involved  is  one  in 
which  great  care,  judgment  and  skill  are  necessary,  particularly 
in  dealing  with  the  degrees  of  heat.  Because  of  its  greater  flexi- 
bility the  welding  heat  of  steel  should  be  lower  than  that  of  iron 
and  thus  the  more  flexible  the  steel  the  harder  it  is  to  weld. 
Mild  steel  can  be  welded  much  more  easily  than  high  carbon  or 
tool  steel.  Ordinary  cast  steel  such  as  double  shear  steel,  con- 
taining as  it  does  a  smaller  proportion  of  carbon  than  "tool 
steel,"  may  be  easily  welded,  as  its  texture,  which  is  very  fibrous, 
is  partly  restored  through  hammering  or  rolling.  Thus  for  all 
edge  tools  for  wood  this  steel  will  give  good  results  as  it  will 
carry  a  very  keen  cutting  edge. 

A  Good  Welding  Flux  for  Steel 

A  good  flux  for  welding  steel  is  sal-ammoniac  and  borax. 
The  borax  of  commerce  as  sold  by  chemists  is  composed  of  a 
very  large  proportion  of  water,  and  in  order  to  use  this,  it  should 
be  put  into  an  iron  or  other  suitable  vessel  and  boiled  over  the 
fire  until  all  the  water  is  expelled,  after  which  it  should  be  ground 
to  a  powder  before  it  is  used.  When  it  is  desired  to  mix  sal- 
ammoniac  with  borax  the  proportions  are  about  16  parts  borax  to 
i  of  sal-ammoniac.  In  heating  a  piece  of  steel  for  forging  it 
should  be  placed  in  the  center  of  a  close  hollow  fire  and  the  wind 
put  on  very  sparingly,  so  as  to  allow  the  mass  to  heat  equally 
through  and  through.  If,  on  the  other  hand,  it  is  put  into  the  fire 
and  the  blast  turned  on  full  the  outside  of  the  metal  will  become 
red  hot  before  the  center;  therefore  the  expansion  of  the  outside 
away  from  the  center  will  cause  internal  strains,  which  will  not 
be  visible  until  the  tool  is  hardened,  and  then  the  hardener  will  be 
blamed. 


176  HARDENING,    TEMPERING    AND    ANNEALING. 

Heating  Steel  for  Forging. 

A  great  many  smiths  say  that  steel  should  not  be  heated  above 
a  cherry  red ;  but  the  best  way  is  to  heat  the  steel  to  as  high  a 
heat  as  it  will  stand  with  safety,  and  draw  down  under  steam 
hammer,  if  there  is  one  handy.  Then  the  whole  mass  will  draw 
down  in  the  center  as  well  as  around  the  outside,  where,  on  the 
contrary,  by  heating  to  a  cherry  red  one  would  only  be  drawing 
the  outside  away  from  the  center,  which  would  show  fracture 
when  cooled.  We  do  not  mean  that  the  steel  should  be  heated 
high  when  the  tool  is  nearly  finished ;  then  the  cherry  red  heat  will 
do,  being  also  careful  not  to  hammer  after  the  red  has  disappeared, 
but  put  it  back  in  the  fire  and  heat  as  evenly  as  possible.  Sulphur 
is  the  greatest  enemy  to  contend  with  in  the  heating  of  steel. 
To  fully  illustrate  the  effects,  heat  a  piece  of  cast  steel  almost  to 
the  scintillating  heat,  and  by  holding  a  piece  of  sulphur  against 
it,  it  will  drop  to  the  floor,  the  same  as  a  piece  of  sealing  wax 
would  do  with  a  match.  A  man  who  is  forging  and  welding  iron 
should  never  be  asked  by  the  foreman  to  dress  a  tool,  as  that 
man  is  blind  to  the  colors  of  steel  which  reveal  themselves  in  the 
tempering. 

Steel  for  Tools  Which  Require  to  be  Forged. 

In  purchasing  tool  steel  for  the  various  kinds  of  tools  that  are 
used  in  metal  working  it  is  best  to  state  to  the  steel  maker  what 
kind  of  tools  the  steel  is  required  for,  as  steel  that  is  suitable  for 
cold  chisels  is  too  low  in  carbon  for  lathe  and  planer  tools.  High 
carbon  steel  cools  far  quicker  under  the  blows  of  the  hammer 
than  low,  and  the  scales  that  fall  from  the  former  are  small  and 
silky  while  the  latter  are  large. 

The  amount  of  working  one  will  get  out  of  a  tool  which  has 
been  properly  forged,  tempered  and  ground  is  unlimited.  It  is  a 
bad  economy  to  buy  cheap  steel  for  tools  of  any  kind.  It  only 
results  in  worry  and  vexation  and  poor  work. 

High  Grade  Steel  Forgings  in  America. 

Few  people  are  probably  aware  of  the  important  change  that 
has  taken  place  in  machine  construction  in  this  country  as  a 
direct  result  of  the  improvements  in  the  manufacture  and  forging 
of  crucible  cast  steel,  first  introduced  by  the  Bethlehem  Steel  Com- 
pany, Pennsylvania,  U.  S.  A.  Without  these  improvements  the 
large  power  units  now  used  in  the  electric  generating  stations 


FORGING    AND    WELDING.  177 

would  have  been  impossible,  for  no  forgings  could  have  been 
obtained  that  would  have  been  able  to  sustain  the  tremendous 
strains  of  such  machinery.  When  steel  forgings  were  first  em- 
ployed for  large  work  they  were  generally  considered  inferior  to 
iron  forgings,  because,  as  is  well  known,  steel  is  not  as  easily 
forged  as  iron  and  is  more  easily  injured  in  the  process,  while' 
the  methods  used  in  forging  were  not  adapted  to  the  requirements 
of  the  new  material.  The  improvements  in  the  manufacture  of 
steel  came  through  the  efforts  of  the  government  to  obtain  steel 
suitable  for  large  guns  and  the  parts  of  marine  engines,  which, 
according  to  law,  had  to  be  built  in  this  country,  and  of  Ameri- 
can material.  A  brief  history  of  how  the  change  of  iron  forgings 
to  high-grade  steel  forgings  came  about,  and  the  manner  in  which 
hollow  shafts  are  forged,  is  given  in  the  following  and  is  taken 
from  a  paper  by  Mr.  H.  F.  J.  Porter,  read  before  the  1902  meet- 
ing of  the  Engine  Builders'  Association : 

At  the  time  George  H.  Corliss  built  his  Centennial  engine  he 
had  his  own  smithshop  in  which  his  shafts  and  other  engine  forg- 
ings were  built  up  out  of  small  fagots  of  wrought  iron.  This 
was  about  the  time  when  steel  began  to  encroach  upon  iron  In  the 
trades.  Before  this  time  wrought  iron  was  a  staple  article  in  the 
market.  The  quality  of  this  material,  coming  from  the  rolling 
mills,  was  very  high,  demands  for  high  grades  having  brought 
about  methods  of  precaution  which  supplied  the  trades  with  ex- 
tra refined  iron,  very  free  from  slag  and  dirt.  The  small  forges 
sparsely  scattered  about  the  country  were  equipped  with  ham- 
mers of  ten  tons  falling  weight  with  top  steam,  sufficient  in  capa- 
city to  thoroughly  work  and  weld  together  the  few  fagots  of 
iron  which  were  required  to  build  up  the  moderate  sized  forgings 
which  the  various  industries  demanded.  When  steel  made  its  ap- 
pearance, however,  manufacturers  generally  began  to  appreciate 
the  fact  that  the  market  contained  a  new  material,  stronger  and 
more  reliable  than  wrought  iron.  Desirous  of  having  the  forged 
parts  of  their  mechanisms  smaller  and  lighter,  they  attempted  at 
once  to  obtain  forgings  made  of  this  metal.  Had  the  forgers 
made  proper  efforts  to  acquaint  themselves  with  the  nature  of 
the  new  material  before  attempting  to  supply  it,  a  very  different 
condition  of  affairs  would  have  come  about,  not  only  in  the  forg- 
ing industry,  but  in  the  steel  industry  at  large,  which  resulted 
from  the  first  unintelligent  effort  at  production.  At  the  meet- 
ing of  the  Railway  Master  Mechanics  and  Master  Car  Builders, 


178  HARDENING,    TEMPERING    AND    ANNEALING. 

at  Old  Point  Comfort,  in  1899,  Captain  (now  Admiral)  Robley 
D.  Evans  delivered  an  address  in  which  he  said : 

"In  1882  I  had  the  good  fortune  to  be  a  member  of  what  is 
known  as  the  first  advisory  board  for  rebuilding  the  navy.  It 
was  an  awfully  hot  summer,  and  fifteen  of  us,  rather  impatient  in 
spirit,  got  together  in  Washington,  presided  over  by  Admiral 
John  Rodgers.  When  we  looked  the  field  over,  we  found  that 
we  had  no  navy  at  all ;  we  were  hopelessly  behind  the  age,  and  it 
seemed  hardly  worth  while  to  rebuild  our  navy.  I  shall  never 
forget  as  long  as  I  live  the  trouble  I  caused  in  that  small  conven- 
tion by  proposing  that  we  should  build  steel  ships.  I  was  the 
original  steel  man,  and  when  I  proposed  that  all  ships  in  future 
should  be  built  of  steel,  Admiral  Rodgers  adjourned  the  board 
for  three  weeks  to  prevent  a  fight." 

Now  the  animus  referred  to  by  Admiral  Evans  was  induced 
by  the  fact  that  forgings  which  were  being  supplied  at  this  time 
were  of  just  such  a  type  as  might  be  expected  to  be  produced  by 
men  who  had  not  acquainted  themselves  with  the  requirements  of 
the  new  material.  While  some  were  excellent  in  every  way,  others 
were  different  in  strength,  or  contained  concealed  cavities  and 
were  unreliable  in  general.  The  supplies  of  material  running  so  ir- 
regular in  quality  reflected  unfavorably  upon  the  steel  industry  at 
large  and  developed  a  prejudice  against  steel  generally,  from 
which  it  has  scarcely  recovered  in  the  minds  of  many  users 
of  forgings,  even  at  the  present  day.  It  was  fortunate  for  the 
country  that  the  advisory  board  referred  to  contained  as  stalwart 
a  champion  of  steel  as  Admiral  Evans,  for  after  they  had  visited 
the  various  ordnance  works  abroad  and  had  seen  steel  worked 
properly,  they  returned  home  and  recommended  to  the  Secretary 
of  the  Navy  Mr.  Tracy,  that  by  all  means  the  new  navy  should 
be  built  of  this  metal,  and  as  there  were  no  properly  equipped 
steel  forges  in  this  country,  one  would  have  to  be  built  .to  furnish 
the  necessary  armor,  guns  and  engine  forgings  required  in  the 
construction  of  modern  naval  war  vessels.  Meanwhile,  this  board 
had  overcome,  through  the  good  offices  of  its  secretary,  the 
personal  objections  heretofore  existing  on  the  part  of  Sir  Joseph 
Whitworth  to  the  use  of  his  special  steel  casting  and  forging 
processes  elsewhere  than  in  his  own  works,  which  were  con- 
sidered foremost  in  the  manufacturing  of  ordnance.  Without 
entering  into  the  details  which  accompanied  the  immediate  estab- 

rtaent   in   this   country   of  the   great   ordnance   works  of   the 


FORGING    AND    WELDING.  179 

Bethlehem  Steel  Company,  it  is  sufficient  to  say  that  in  their 
equipment  not  only  were  special  appliances  in  use  in  this  English 
works  duplicated,  but  their  size  was  doubled.  A  contract  was 
also  entered  into  at  the  same  time  by  which  the  great  works  of 
Schneider  &  Co.,  of  Le  Creusot,  France,  which  stood  first  among 
the  makers  of  armor  plate,  were  also  duplicated  at  the  Bethle- 
hem plant.  Thus  there  arose  in  this  country  a  forging  plant  at 
once  larger  and  superior  to  any  in  the  world. 

During  the  years  this  plant  was  being  erected  there  were 
many  engineers  who,  appreciating  the  superior  advantages  of  steel 
forgings  when  properly  produced  over  those  made  of  wrought 
iron,  systematically  sent  abroad  for  their  steel  forgings.  It  was  not 
until  1889  that  the  country  obtained  its  first  high-grade  steel 
commercial  forgings  from  the  Bethlehem  works.  These  had 
been  gladly  specified  by  the  engineers  above  mentioned  who  were 
impatiently  waiting  to  get  their  steel  forgings  nearer  home  than 
in  Europe.  Machine  and  tool  builders  of  this  country  were  thus 
made  acquainted  for  the  first  time  with  steel  forgings  intelli- 
gently produced.  There  are  to  this  day  many  users  of  steel  forg- 
ings who,  not  having  carefully  investigated  the  methods  con- 
sidered necessary  to  produce  them,  think  that  a  steel  forging 
is  made  by  merely  hammering  a  rolled  steel  billet  to  the  form 
required ;  and  such  as  order  their  forgings  without  specifying 
more  definitely  the  grade  called  for  by  the  special  service  to 
which  the  forging  is  to  be  submitted  may  get  a  forging  of  that 
type.  The  forging  industry  has  grown  from  the  blacksmith 
shop,  a  once  familiar  adjunct  to  an  engine  works,  and  has  become 
a  specialty ;  and  a  modern  steel  forge  is  not  now  thought  com- 
plete unless  it  melts  its  own  raw  material  and  converts  it  into 
the  finished  product  under  the  supervision  of  chemists,  metallurg- 
ists, physicists  and  microscopists. 

Hozv  Hollow  Shafts  Are  Forged. 

There  are  two  ways  of  making  a  forging  hollow.  The  ordi- 
nary way  of  getting  rid  of  the  center  of  a  forging  is  simply  to 
bore  it  out.  After  boring,  it  is  tempered  and  thus  jhe  strength  is 
restored  which  was  taken  away  with  the  material  which  was 
in  the  center. 

Another  way  of  getting  rid  of  the  center  of  large  forgings 
is  to  forge  them  hollow.  A  person  who  has  not  considered  the 
subject  carefully  would  naturally  think  that  the  first  thing  to  do  j 


l8o  HARDENING,    TEMPERING    AND    ANNEALING. 

making  a  hollow  forging  would  be  to  cast  a  hollow  ingot.  It  has 
been  mentioned  that  there  were  various  defects  which  occur  in 
ingots,  the  most  serious  of  which  are  "segregation"  and  "piping" 
and  that  it  is  in  the  center  and  upper  portion  where  those  defects 
occur.  If  an  ingot  were  to  be  cast  hollow,  a  solid  core  of  fire- 
brick or  similar  material  would  replace  the  center  metal,  and 
instead  of  one  on  the  outside  there  would  be  two  cooling  surfaces, 
one  on  the  outside  and  one  around  the  core,  and  the  position  of 
the  last  cooling  would  be  transferred  to  an  annular  ring,  midway 
between  these  surfaces,  where  the  "piping"  and  "segregation" 
would  collect.  This  would  not  be  satisfactory,  because  the  metal 
there  is  what  must  be  depended  upon  for  the  strength  of  the 
hollow  forging.  It  is  necessary,  therefore,  to  collect  the  "piping" 
and  "segregation"  in  the  center  and  the  top,  where  the  metal  has 
been  added  to  the  original  ingot  for  the  purpose. 

Then  having  cut  off  the  top  and  bored  out  the  center,  the 
"piping"  and  "segregation"  are  entirely  eliminated  and  what  is 
left  is  as  sound  and  homogeneous  a  piece  of  steel  as  can  be 
obtained. 

After  the  hole  has  been  bored  in  the  ingot,  the  next  process  is 
to  re-heat  it,  and,  as  before  explained,  this  process  is  not  as  de- 
licate a  one  as  if  the  ingot  were  solid.  The  heat  affects  the  center 
equally  with  the  interior  and  they  expand  together  and  the 
danger  of  cracking  is  not  incurred.  When  the  ingot  is  re- 
heated a  steel  mandrel  is  put  through  its  hollow  center,  and  sub- 
jecting the  two  to  hydraulic  pressure  the  metal  is  forced  down 
and  out  over  the  mandrel.  Thus  an  internal  anvil  is  practically 
inserted  into  the  forging  and  there  is,  therefore,  really  much  less 
than  one-half  the  amount  of  metal  to  work  on  than  if  the  piece 
were  solid. 

When  the  work  of  shaping  is  completed  the  forging  is  re- 
heated to  the  proper  temperature  and  then  either  annealed  in  the 
usual  manner  or  plunged  into  a  tempering  bath  of  oil  or  brine,  to 
set  the  fine  grain  permanently  that  has  been  established  by  the  re- 
heating. A  mild  annealing  follows  to  relieve  any  surface  or  other 
strains  that  may  have  been  occasioned  by  the  rapid  cooling. 

Hollow  forcings  oil-tempered  and  annealed  are  considered  the 
best  grade  of  forgings  made,  and  any  forgings  made  otherwise, 
although  they  may  be  suitable  for  the  service  to  which  they  may 
be  applied,  cannot  be  looked  upon  in  any  other  manner  than  as 
of  an  inferior  grade. 


FORGING    AND    WELDING.  l8l 

That  steel  forgings  of  such  high  grade  were  being  manufac- 
tured for  commercial  purposes  in  this  country  was  first  brought 
to  the  attention  of  manufacturers  generally  at  the  World's  Fair 
in  Chicago.  Here  were  exhibited  stationary  engine  forgings 
which  compared  favorably  with  those  sent  over  by  European 
forges.  The  Ferris  wheel  shaft,  45  feet  long  and  32  inches  out- 
side diameter,  with  a  1 6-inch  hole  through  it,  represented  the 
largest  made  up  to  that  time.  The  soliciting  of  orders  for  such 
forgings,  however,  at  once  aroused  the  latent  prejudice  still  ex- 
isting against  steel  forgings,  and  the  prices  demanded  being  some- 
what in  excess  of  those  which  wrought  iron  or  ordinary  steel 
forgings  could  be  obtained  for,  prevented  at  first  the  very  rapid 
introduction  of  this  product  into  the  commercial  field. 

Difficulties  Encountered  in  Introducing  High-Grade  Forgings. 

It  hardly  seemed  necessary  to  explain  to  an  engineer  or  any 
one  authorized  to  purchase,  and  therefore  presumably  competent, 
that  if  he  wanted  material  to  sustain  severe  usage  in  the  nature  of 
alternating  stresses,  to  which  all  forgings  are  subjected,  he  should 
select  a  material  possessing  a  very  high  elastic  limit.  And  yet  it 
was  not  unusual  to  find  that  those  very  people  preferred  to  use 
wrought  iron  for  their  engine  crosshead  and  crank  pins  and 
shafts  in  preference  to  steel,  because,  as  they  said,  "steel  being 
crystalline  is  brittle  and  snaps  off  suddenly  under  such  services 
as  that  under  consideration,  while  iron  having  fiber,  is  tougher 
and  yields  before  breaking."  Most  of  these  men  know  better, 
but  had  not  given  the  subject  sufficient  thought,  or  they  would 
have  perceived  that  their  statements  were  not  consistent.  They 
said  that  the  steel  connecting  rods  they  had  tried  had  broken  off 
short  without  any  warning,  while  rods  made  of  wrought  iron  had 
simply  bent  up,  and  after  having  been  straightened  out  were  re- 
placed as  good  as  new. 

These  people  did  not  stop  to  think  that  a  steel  rod  that  broke 
off  had  done  so  at  its  ultimate  strength,  or  under  a  stress  of  from 
80,000  to  90,000  pounds  per  square  inch,  whereas  the  iron  rod 
which  had  doubled  up  had  done  so  at  its  yielding  point  of  25,000 
to  30,000  pounds  per  square  inch.  In  other  words,  their  engines 
with  wrought  iron  rods  were  failing  all  over  the  country  under 
loads  about  one-third  what  they  were  standing  up  to  when  sup- 
plied with  steel  rods,  yet  the  men  were  blaming  the  steel  for  help- 
ing them  out  of  their  troubles. 


l82  HARDENING,    TEMPERING    AND    ANNEALING. 

Then  again  they  complained  that  steel  shafts  and  crank  pins 
heated  up,  while  wrought  iron  ran  cool.  When  it  was  proved  to 
them  that  laboratory  experiments  showed  the  coefficient  of  friction 
of  these  metals  to  be  the  same,  and  that  any  difference  in  heating- 
was  caused  by  local  circumstances,  such  as  poor  lubrication,  ex- 
cessive pressure,  etc.,  they  said  they  did  not  care  for  laboratory 
experiments.  They  had  an  engine  in  one  place  with  a  steel  shaft 
that  never  would  run  cool,  while  another  with  a  wrought-iron 
shaft  had  never  given  any  trouble,  and  they  were  passing  judg- 
ment on  their  own  experience.  Persistent  exposure  of  these  fal- 
lacies gradually  brought  about  a  change  in  sentiment. 

"Cold  Crystallization"  Does  Not  Occur. 

It  took  a  long  time  to  persuade  people  who  had  seen  broken 
fcrgings  which  showed  a  coarse  crystalline  section  that  the 
metal  had  not  crystallized  from  shock  or  vibration  in  service, 
but  had  been  forged  in  such  a  manner  that  the  crystallized 
condition  of  the  ingot  from  which  the  forging  had  been 
made  had  not  been  changed  by  the  forging  process  or  by 
subsequent  heat  treatment.  And  these  are  the  people  even  now 
who  consider  themselves  conservative,  who  would  rather  have 
their  forgings  made  of  a  mild  steel  which  is  weak,  than  of  a  high- 
carbon  steel  which  is  strong,  simply  because  the  old  ideas  are  not 
yet  eradicated  from  their  minds.  Tests  were  made  at  the  gov- 
ernment testing  bureau  at  Watertown  by  rapidly  bending  bars 
forward  and  backward  within  their  elastic  limit,  with  the  follow- 
ing results,  and  these  have  given  engineers  an  idea  of  the  com- 
parative endurance  of  wrought  iron,  steel  and  nickel  steel,  m 
such  service  as  that  to  which  crank  pins,  shafts,  etc.,  are  subject. 

Tests  of  Steel  Under  Repeated  Stresses. 

Under  a  Fiber  Stress  of  40,000  Pounds  per  Square  Inch. 

Wrought  iron  breaks  after     50,000  alternations  of  stress. 
.15  p.  c.  carbon    steel  "       170,000 

-25  P- c.  "      229,000 

-35  P- c.  «      317,000 

-45  P-  c.  "      976.000  "  " 

3>4  P-  c.  nickel  steel,  carbon  .25  to  .30  p.  c.,  1,850,000  alternations  of  stress. 
4/2  P-  c.  .25  to  .30  p.  c.,  2,360,000 

51/?  P-  c.  "        .25  to  .30  p.  c.,  4,370,000          " 

Charcoal. 
The  best  qualities  of  charcoal  are  made  from  oak,  maple,  beech 


FORGING   AND    WELDING.  183 

and  chestnut.  Between  5  and  17  per  cent  of  coal  will  be  ob- 
tained when  the  wood  has  been  properly  burned.  A  bushel  of 
coal  from  hardwood  weighs  from  29  to  31  pounds  and  from 
pine  28  to  30  pounds. 

Welding  Powder  for  Iron  and  Steel. — For  welding  iron  and 
steel  a  composition  has  lately  been  patented  in  Belgium,  consisting 
of  iron  filings,  40  parts ;  borax,  20  parts ;  balsam  of  copaiba  or 
some  other  resinous  oil,  2  parts,  and  sal-ammoniac,  3  parts.  They 
are  mixed,  heated  and  pulverized.  The  process  of  welding  is 
much  the  same  as  usual.  The  surfaces  to  be  welded  are  powdered 
with  the  composition  and  then  brought  to  a  cherry  red  heat,  at 
which  the  powder  melts,  when  the  portions  to  be  united  are  taken 
from  the  fire  and  joined.  If  the  pieces  to  be  welded  are  too 
large  to  be  introduced  at  the  same  time  into  the  forge,  one  can 
be  first  heated  with  the  welding  powder  to  a  cherry  red  heat  and 
then  others  afterward  to  a  white  heat,  after  which  the  welding 
may  be  effected. 

To  Make  Edge-Tools  from  Cast-Steel  and  Iron. — This  method 
consists  in  fixing  a  clean  piece  of  wrought  iron,  brought  to  a 
welding  heat,  in  the  center  of  the  mould,  then  pouring  in  melted 
steel,  so  as  to  entirely  envelop  the  iron,  and  then  forging  the 
mass  into  the  shape  required. 

To  Weld  Cast-Iron. 

Take  3  parts  of  good  class  white  sand,  refined  solution  fost- 
ering and  rock  salt  of  each  i  part ;  heat  the  pieces  to  be  welded 
in  a  charcoal  fire,  occasionally  taking  out  and  dipping  into  the 
composition,  until  they  are  of  a  proper  heat  to  weld.  Then 
take  immediately  to  the  anvil  and  weld  together.  If  done  care- 
fully by  one  who  understands  welding  iron,  there  will  be  a  good 
strong  weld. 

Welding  Composition  for  Cast-Steel. — Take  borax,  10  parts; 
sal-ammoniac,  i  part ;  grind  or  pound  them  roughly  together,  then 
fuse  them  in  a  metal  pot  over  a  clear  fire,  taking  care  to  con- 
tinue the  heat  until  the  spume  has  disappeared  from  the  surface. 
When  the  liquid  appears  clear,  the  composition  is  ready  to 
be  poured  out  to  cool  and  concrete ;  afterward,  being  ground 
to  a  fine  powder,  it  is  ready  for  use.  To  use  this  composition, 
the  steel  to  be  welded  is  first  raised  to  a  bright  yellow  heat, 
it  is  then  dipped  into  the  welding  powder,  and  again  placed  in 


184  HARDENING,    TEMPERING    AND    ANNEALING. 

the  fire  until  it  attains  the  same  degree  of  heat  as  before;  it  is 
then  ready  to  be  placed  under  the  hammer. 

How  to  Restore  Overheated  Steel. 

A  number  of  receipts  for  compositions  which  will  restore  over- 
heated steel  are  given  in  the  following: 

To  Restore  Overheated  Cast-Steel. — Take  i~y2  pounds  borax, 
1/2  pound  sal-ammoniac,  i/4  pound  prussiate  potash,  i  ounce 
rosin.  Pound  the  above  fine,  add  a  gill  each  of  water  and  alcohol. 
Put  in  an  iron  kettle,  and  boil  until  it  .becomes  paste.  Do  not  boil 
too  long  or  it  will  become  hard  on  cooling. 

To  Restore  Overheated  Steel. — Borax  3  pounds ;  sal-ammon- 
iac, i  pound ;  prussiate  potash,  y2  pound ;  alcohol,  i  gill ;  soft 
water,  i  pint.  Put  into  an  iron  pan  and  hold  over  a  slow  fire  until 
it  comes  to  a  slow  boil  and  until  the  liquid  matter  evaporates ;  be 
careful  to  stir  it  well  from  the  bottom  and  let  it  boil  slow.  This 
receipt  is  very  valuable;  no  matter  how  badly  the  steel  is  over- 
heated it  will  restore  and  make  it  as  durable  as  ever. 

To  Restore  Overheated  Steel  and  Improve  Poor  Steel. 

Borax,  3  ounces ;  sal-ammoniac,  8  ounces ;  prussiate  of  potash, 
3  ounces;  blue  clay,  2  ounces;  rosin,  ii/>  pounds;  water,  i  gill; 
alcohol,  i  gill.  Put  all  over  a  slow  fire ;  let  it  simmer  until  it  dries 
to  a  powder.  Heat  the  steel  not  above  a  cherry  red ;  dip  into  this 
powder  and  afterwards  hammer. 

Composition  to  Toughen  Steel. — Rosin  2%  pounds ;  tallow  2i/2 
pounds;  pitch  i1/^  pounds.  Melt  together  and  apply  to  the  steel 
while  hot. 

Pointer. 

Rosin  on  the  blacksmith's  forge  improves  and  toughens  steel. 
When  the  tool  is  hot,  dip  it  into  the  rosin,  then  hammer. 

To   Weld  Buggy  Springs. 

To  weld  buggy  springs  first  scarf  one  piece  of  spring,  and 
then  weld  onto  it  a  piece  of  spring  cut  off  about  three-quarters 
of  an  inch  longer  than  the  first ;  heat  and  upset  until  one-quarter 
thicker  at  end  than  spring  scarf.  Now  upset  the  other  piece 
until  as  near  thickness  of  first  piece  as  possible ;  scarf  and  weld. 
Leave  a  trifle  heavier  at  weld,  and  if  the  work  has  been  done 
properly  the  weld  can  be  warranted  not  to  break.  Use  a  41/2 
pound  hammer  in  making  this  weld,  and  keep  at  it  until  finished. 


FORGING    AND    WELDING. 


A  French  Welding  Flux. 

In  using  a  flux,  as  is  necessary  when  welding  steel,  or  iron 
and  steel,  it  is  oftentimes  difficult  to  keep  the  flux  in  place  on 


FIG.   128. — 1,500-POUND    FRICTION    ROLL,   FORGING   DROP   WITH 
GEARLESS   LIFTER. 

account  of  its  quickly  melting  and  running  off  the  weld.  M.  J. 
Lafitte,  Paris,  France,  has  devised  a  flux  consisting  of  a  borax 
mixture  in  which  is  incorporated  a  fine  wire  netting  to  hold  it 


i86 


HARDENING,    TEMPERING    AND   ANNEALING. 


FORGING   AND    WELDING.  187 

together.  It  is  rolled  out  in  thin  sheets  and  divided  into  squares 
which  are  easily  broken  apart  for  use.  Tests  of  steel  specimens 
welded  in  the  French  government  works  show  a  remarkably 
high  efficiency  of  the  welds.  This  is  due  to  the  high  protective 
power  of  the  flux  which  prevents  the  formation  of  oxide  on  the 
surface  of  the  welds. 

Compound  for  Welding  Steel. — The  following  composition 
has  in  a  number  of  cases  proved  superior  to  borax  for  welding 
steel :  Mix  coarsely  powdered  borax  with  a  thin  paste  of  prussi- 
ate  blue;  then  let  it  dry. 

Fluxes  for  Soldering  and  Welding. 

For  iron  or  steel,  borax  or  sal-ammoniac ;  tinned  iron,  rosin  or 
chloride  of  zinc ;  copper  and  brass,  sal-ammoniac  or  chloride  zinc ; 
zinc,  chloride  of  zinc ;  lead,  tallow  or  rosin ;  lead  and  tin  pipes, 
rosin  and  sweet  oil. 

Substitute  for  Borax  in   Welding. 

Copperas,  2  ounces  ;  saltpeter,  i  ounce ;  common  salt,  6  ounces  ; 

black  oxide  of  manganese,  i  ounce ;  prussiate  of  potash,  I  ounce. 

All  pulverized  and  mixed  with  3  pounds  good  welding  sand. 

•  High  carbon  steel  can  be  welded  with  this  at  a  lower  heat 

than  is  required  with   borax. 

Drop-Forgings. 

Drop  forging  is  the  art  of  forging  with  drop  hammers  and 
may  be  designated  as  "machine  blacksmithing."  The  inception  of 
the  art  dates  back  to  about  1853  when  Colonel  Samuel  Colt 
adopted  drop-hammers  to  make  parts  for  firearms.  The  ma- 
chines, processes  and  tools  used  in  the  art  have  since  been  greatly 
improved  and  the  products  of  the  drop  forging  industry  are  now 
used  in  a  majority  of  the  mechanical  arts.  Figs.  130  to  140 
illustrate  parts  produced  by  drop  forging. 

The  dies  used  for  making  drop-forgings  are  made  in  two 
parts.  One  part  (the  upper)  is  fastened  in  the  ram  or  hammer 
of  the  drop,  which  moves  vertically  between  two  uprights  or  guides 
and  is  raised  by  means  of  friction  rolls  controlled  by  the  operator. 
The  other  part  of  the  die  (the  lower)  is  fixed  in  the  anvil  or 
base  of  the  hammer.  The  ram  raises  until  released,  when  it  falls 
instantly,,  striking  with  the  upper  die  the  heated  bar  of  metal 
placed  on  the  bottom  die  and  forcing  it  into  impressions  in  both 
dies.  By  a  series  of  such  blows  the  complete  article  is  formed. 


188 


HARDENING,    TEMPERING   AND   ANNEALING. 


An  idea  of  the  extensive  use  to  which  drop-forgings  have 
been  put  may  be  gained  from  the  fact  that  J.  H.  Williams  & 
Co.,  of  Brooklyn,  N.  Y.,  a  company  devoted  exclusively  to  the 
making  of  drop-forgings,  started  in  1889  w^  a  forging  plant  of 
three  drop-hammers,  and  it  now  consists  of  forty-three  drop- 
hammers,  with  trip-hammers,  steam  hammers,  upsetting  ma- 
chines and  other  apparatus. 

The  necessary  dies  used  to  produce  drop-forging  of  special 
shapes  and  sizes  are  usually  made  from  a  drawing  or  model,  pre- 
ferably the  latter  as  it  facilitates  designing  the  dies  and  allows 


FIG.  130. — DROP-FORGED  CRANK  SHAFTS. 


of  figuring  the  cost  of  the  tools  much  easier  than  could  be  done 
from  a  drawing. 

In  making  drop-forging  dies  the  die  sinker  must  know  whether 
the  drawing  and  model  show  finished  or  forging  size;  he  needs 
also  to  know  the  allowance  desired  in  machining.  It  is  usual 
to  add  1-32  inch  on  each  surface  to  be  machined  unless  the  piece 
is  to  be  finished  by  grinding  or  polishing  only,  in  which  case  i-ioo 
inch  is  allowed ;  surfaces  not  to  be  machined  or  ground  are  made 
close  to  size.  Forgings  vary  slightly  in  thickness — say  from 
i-ioo  inch  to  1-32  inch — depending  on  their  shape  and  the  ma- 
terial used.  They  can,  however,  be  made  to  gage  by  a  re-striking 
operation ;  this  operation  requires  separate  dies  and  entails  addi- 
tional expense. 


FORGING   AND    WELDING.  189 


FIG.   131. — DROP-FORGED  WRENCHES. 


190 


HARDENING,    TEMPERING    AND    ANNEALING. 


In  addition  to  forging  dies,  the  cost  and  endurance  of  which 
depend  upon  the  work  required  of  them,  trimming  dies  are  neces- 


FIG.  132. — SPECTAI,   DROP-FORCINGS. 


FIG.    133. — SPECIAL    DROP-FORGING. 


sary  to  remove  the  surplus  metal  thrown  out  between  the  forg- 
ing dies  in  working. 

Before  using  the  finished  set  of  dies  for  forging,  a  lead  proof 
is  struck  up  which  is  submitted  to  the  customer.    The  proof  often 


FORGING   AND    WELDING.  IQI 

varies  from  the  model  or  drawing  by  what  is  called  draft.  This 
is  the  taper  necessary  on  the  forgings  to  allow  of  drawing  them 
from  the  dies  while  working,  and  it  averages  about  seven  degrees. 
It  can  be  obtained  by  adding  to  or  taking  from  the  forging ; 
usually  the  draft  metal  is  added. 

Establishments  devoted  exclusively  to  the  manufacture  of  drop 
forgings  carry  a  large  and  assorted  stock  of  material  from  which 
to  make  the  forgings.  But  in  new  dies,  where  the  size  of  metal 
required  cannot  be  determined  until  they  are  tried  in  the  hammer, 
delays  in  obtaining  the  right  sizes  sometimes  occur.  As  poor  ma- 
terial cannot  be  used,  drop-forgings  are,  therefore,  not  only 
superior  to  hand-forgings  because  the  metal  is  improved  by  the 


FIG.  134. — DROP-FORGED  FIG.  135. — DROP-FORGED 

GEAR.  BRACKETS. 


forging  operation,  but  also  because  the  nature  of  the  process 
requires  a  good  quality  of  material. 

Forgings  from  steel  of  high  carbon  usually  require  annealing 
before  they  can  be  machined.  While  making  drop-forgings  they 
are  carefully  brushed  with  steel  wire  brushes  to  remove  the  scale, 
but  if  they  are  to  be  machined  they  are  pickled  in  diluted  sul- 
phuric acid  to  insure  the  complete  removal  of  the  hard  outer  skin. 
Often  small  drop-forgings  are  tumbled  instead  of  pickled. 

Those  who  require  drop-forgings  will  be  saved  undue  expense 
if  they  inform  manufacturers  of  the  use  for  which  the  forgings 
are  intended.  The  price  is  largely  affected  by  the  quantities  made 
with  one  setting  of  the  tools.  It  costs  as  much  to  set  dies  for  100 
as  for  1,000  pieces,  and  the  forging  work  is  also  more  costly  in 
small  lots.  Prices  for  special  drop-forging  are  made  per  piece, 


10,2  HARDENING,    TEMPERING    AND    ANNEALING. 

not  per  pound,  and  vary  with  the  nature  of  the  work,  the  material 
used  and  the  quantity  taken. 

The  cheapest  drop-forgings  in  the  long  run  are  those  most  uni- 
form in  size  and  quality  and  close  to  finish  dimensions,  thus  sav- 
ing labor,  time,  tools  and  money. 

Directions  for  Setting  up  Forging  Drop-Hammers. 
It  is  very  important  to  have  a  good  foundation,  and  we  recom- 
mend as  the  cheapest  and  best,  when  it  can  be  obtained,  a  log 
large  enough  in  diameter  at  the  butt  end  for  the  drop  to  stand 
on,    and    long   enough   to   enter   the   ground    six    or   eight    feet. 


FIG.   136. — SPECIAL   DROP-  FIG.    I  37.— DROP  FORGED 

FORCINGS.  BRACKET. 

First  dig  a  hole  one  foot  deeper  than  is  necessary  to  receive  the 
log,  and  large  enough  to  leave  a  space  of  about  one  foot  all 
around  it.  Before  the  log  is  put  into  the  hole,  fill  the  bottom  with 
grout  one  foot  deep ;  then,  after  placing  the  log  in  the  hole  so  that 
it  will  stand  perpendicular,  grout  it  nearly  to  the  top  of  the 
ground. 

For  light  drops,  it  will  do  very  well  to  put  a  large  flat  stone 
under  the  bottom  of  the  log  and  fill  it  with  earth,  well  stamped 
down.  Now  adze  the  top  of  the  log  level ;  then  make  a  depres- 
sion in  the  center  of  the  surface,  about  six  inches  square  and  two 
inches  deep,  with  a  groove  about  one  inch  wide  leading  to  the 


FORGING    AND    WELDING. 


193 


edge  of  the  block,  to  allow  the  scales  and  dirt  to  pass  off,  and 
not  to  get  under  the  drop  to  make  it  rock  or  it  will  be  unsteady. 
When,  because  of  the  size  of  the  drop,  or  for  other  reasons,  a  log 
cannot  be  obtained  large  enough  to  put  it  on,  take  numbers,  say 
one  foot  square,  and  bolt  enough  of  them  together  to  make  it  of 
suitable  size,  when  set  up  on  end  to  receive  the  drop.  Grout,  and 
fill  in,  in  the  same  manner  as  for  the  log.  Chestnut  and  oak  are 
the  best. 

For  forging  drops  with  hammers  weighing  1,000  to  2,000 
pounds,  some  manufacturers  build  a  masonry  foundation  8  to  12 
feet  square  at  the  base,  tapering  to  the  size  of  anvil  shape  at  the 
top,  and  10  to  14  feet  deep,  with  about  4  feet  in  height  of  oak 


FIG.  139. — DROP-FORGED 
YOKE. 


FIG.  138. — DROP-FORGED 
HOOK. 


FIG.  140. — DROP-FORGED 
SHAFT  BRACKET. 


timbers  at  the  top  bolted  together  on  end.  The  hole  around  this 
foundation  is  then  filled  with  .grouting.  If  only  a  rock  or  stone 
foundation  can  be  had,  place  about  one-half  inch  of  sheet  rubber 
or  rubber  belting  under  the  bottom  of  the  drop.  There  is  danger 
of  getting  a  foundation  too  solid  for  a  drop.  There  should  be 
some  elasticity,  and  when  set  on  a  log  or  timber  the  desired 
effect  is  obtained ;  and  when  placed  upon  stone  the  rubber  belting 
is  sufficient.  A  suitable  foundation  having  now  been  obtained, 
and  the  drop  fastened  to  the  same  on  a  line  with  a  shaft  that  is 
to  drive  it,  brace  the  drop  at  the  top  by  rods,  one  end  of  which 
can  be  secured  to  the  building,  and  the  other  to  the  lifter,  in 
holes  provided  for  that  purpose.  The  belts  must  run  back  away 
from  the  operator. 


194  HARDENING,    TEMPERING    AND    ANNEALING. 

Government   Use  of  Nickel  Steel  for  Forgings. 

With  a  view  to  their  utilization  in  the  various  mechanical  de- 
partments of  the  government  of  the  United  States,  the  Bureau  of 
Steam  Engineering  has  undertaken  extensive  experiments  with 
various  metals.  One  result  already  is  the  adoption  of  nickel  steel  for 
forgings  and  other  parts  of  steam  engines.  It  is  contended  that 
the  principal  advantage  of  nickel  steel  over  ordinary  carbon  steel 
for  forgings  lies  in  the  relation  which  the  elastic  limit  bears  to 
the  tensile  strength,  the  former  being  in  a  sense  the  true  strength 
of  the  metal.  The  elastic  limit  of  nickel  steel  is  much  higher 
than  that  of  carbon  steel  of  the  same  tensile  strength  and  elonga- 
tion, very  often  30  per  cent  higher  and  in  some  cases  as  much 
as  50  per  cent  higher.  The  principal  drawback  to  the  commer- 
cial use  of  nickel  steel  has  been  the  first  cost  of  producing  it, 
which  in  many  cases  is  higher  than  the  cost  of  ordinary. finished 
forgings. 

A  decided  virtue  of  nickel  steel,  according  to  government 
report,  is  the  facility  with  which  a  low  carbon  steel  will  harden, 
it  being  the  practice  after  a  forging  is  forged  and  rough  ma- 
chined, to  heat  it  and  quench  it  in  oil,  which  hardens  it  very 
much;  afterward  the  forging  is  submitted  to  an  annealing  pro- 
cess which  removes  any  strains  set  up  in  the  metal  by  the  sudden 
cooling  which  it  receives.  Nickel  steel,  after  the  first  cost  of 
production,  is  not  much  more  expensive  to  forge  than  any  carbon 
steel  that  runs  over  .40  per  cent  carbon,  and  about  the  same  care 
is  necessary  in  heating  and  forging  as  is  required  by  a  high  car- 
bon steel. 


CHAPTER  XL 

MISCELLANEOUS   METHODS,   PROCESSES,   KINKS,  POINTS  AND  TABLES 
FOR    USE    IN    METAL   WORKING. 

Increasing  the  Size  of  a  Reamer  When  Worn. 

To  increase  a  reamer  to  size  when  w'orn,  burnish  the  face  of 
each  tooth  with  a  hardened  burnisher,  which  can  be  made  from  a 
three-cornered  file  nicely  polished  on  the  corners.  This  will  in- 
crease the  size  from  2  to  10  thousandths  in  diameter.  Then  hone 
back  to  the  required  size. 

To  make  a  tap  or  reamer  cut  larger  than  itself,  put  a  piece 
of  waste  in  one  flute,  enough  to  crowd  it  over  and  cut  out  on  one 
side  only.  In  larger  sizes  (i~y2  inch  or  over)  put  a  strip  of  tin 
on  one  side  and  let  it  follow  the  tap  through. 

To  Case-Harden  Cast- Iron. 

Heat  to  a  red  heat,  roll  in  a  composition  consisting  of  equal 
parts  of  prussate  of  potash,  sal-ammoniac  and  saltpeter,  pulver- 
ized and  thoroughly  mixed.  Plunge  while  yet  hot  into  a  bath  con- 
taining 2  ounces  of  prussate  of  potash  and  2  ounces  of  sal-am- 
moniac to  each  gallon  of  cold  water. 

Rules  for  Calculating  Speed. 

The  diameter  of  driven  given  to  find  its  number  of  revolu- 
tions : 

Rule. — Multiply  the  diameter  of  the  driver  by  its  number  of 
revolutions  and  divide  the  product  by  the  diameter  of  the  driven. 
The  quotient  will  be  the  number  of  revolutions  of  the  driven. 

The  diameter  and  revolutions  of  the  driver  being  given  to  find 
the  diameter  of  the  driven  that  shall  make  any  number  of  revolu- 
tions : 

Rule. — Multiply  the  diameter  of  the  driver  by  its  number  of 
revolutions  and  divide  the  nroduct  by  the  number  of  required  rev- 
olutions of  the  driven.  The  nuotient  will  be  its  diameter. 

To  ascertain  the  size  of  millevs  for  given  speeds : 

Rule. — Multiply  all  the  diameters  of  the  drivers  together  and 
all  the  diameters  of  driven  together;  divide  the  drivers  by  the 


196  HARDENING,    TEMPERING    AND    ANNEALING. 

driven.     Multiply  the  answer  by  the  known  number  of  revolu- 
tions of  main  shaft. 

Improved  Soldering  or  Tinning  Acid. 

Muriatic  acid  i  pound;  put  into  it  all  the  zinc  it  will  dissolve 
and  i  ounce  of  sal-ammoniac,  then  it  is  ready  for  use. 

Lubricant  for  Water  Cuts. 

Strong  sal  soda  water  cr  soap  water  is  much  better  than  clear 
water  to  use  where  water  cuts  are  being  taken,  either  on  lathe  or 
planer. 

Babbitting. 

Put  a  piece  of  rosin  the  size  of  a  walnut  into  your  Babbitt ; 
stir  thoroughly,  then  skim.  It  makes  poor  Babbitt  run  better, 
and  improves  it.  Babbitt  heated  just  hot  enough  to  light  a  pine 
stick  will  run  in  places  with  the  rosin  in,  where,  without  it,  it 
would  not.  It  is  also  claimed  that  rosin  will  prevent  blowing 
when  pouring  in  damp  boxes. 

Laying  Out  Work. 

In  laying  out  work  on  planed  or  smooth  surfaces  of  steel  or 
iron,  use  blue  vitriol  and  water  on  the  surface.  This  will  copper- 
over  the  surface  nicely,  so  that  all  lines  will  show  plainly.  If  on 
oily  surfaces,  add  a  little  oil  of  vitriol ;  this  will  eat  the  oil  off 
and  leave  a  nicely  coppered  surface. 

Lubricant  for   Working  Aluminum. 
Use  kerosene  oil  (coal  oil)  for  drilling  or  turning  aluminum. 

To  Prevent  Rust. 

To  prevent  rust  on  tools,  use  vaseline,  to  which  a  small 
amount  of  powdered  gum  camphor  has  been  added ;  heat  together 
over  a  slow  fire. 

Lubricant  for  Drilling  Hard  Steel. 

Use  turpentine  instead  cf  oil  when  drilling  hard  steel,  saw 
plates,  etc.  It  will  drill  readily  when  you  could  not  touch  it  with 
oil. 

Coppering  Polished  Steel  Surfaces. 

To  copper  the  surface  of  iron  or  steel  wire,  have  the  wire  per- 
fectly clean,  then  wash  with  the  following  solution,  when  it  will 


MISCELLANEOUS    METHODS,  TABLES,  ETC.  IQ7 

present  at  once  a  coppered  surface:     Rain  water,  3  pounds;  sul- 
phate of  copper,  i  pound. 

To  Blue  Steel  Without  Heating. 

To  blue  steel  without  heating,  apply  nitric  acid ;  then  wipe  off 
the  acid,  clean,  oil  and  burnish. 

To  Remove  Scale  from  Steel. 

Scale  may  be  removed  from  steel  articles  by  pickling  in  water 
with  a  little  sulphuric  acid  in  it,,  and  wHhen  the  scale  is  loosened, 
brushing  it  with  sand  and  stiff  brush. 

To  Distinguish  Wrought  and  Cast-Iron  from  Steel. 
Elsiner  produces  a  bright  surface  by  polishing  or  filing,  and 
applies  a  drop  of  nitric  acid,  which  is  allowed  to  remain  there 
for  one  or  two  minutes,  and  then  washed  off  with  water.  The 
spot  will  look  a  pale  ashy  gray  on  wrought-iron,  a  brownish  black 
on  steel,  a  deep  black  on  cast-iron.  It  is  the  carbon  present  in  var- 
ious proportions  which  produces  the  difference  in  appearance. 

Anti-Friction   Alloy  for  Journal  Boxes. 
Zinc,  17  parts;  copper,  I  part;  antimony,  y2  part. 
This  possesses  unsurpassable  anti-friction  qualities  and  does 
not  require  the  protection  of  outer  castings  of  the  harder  metal. 

Solder  for  Aluminum. 

A  great  drawback  to  the  use  of  aluminum  for  many  purposes 
is  the  difficulty  of  soldering  it.  A  number  of  solders  are  known 
that  are  fairly  successful  when  manipulated  by  skillful  hands. 
The  following  one  was  recommended  by  Prof.  E.  Wilson  in  a 
paper  read  before  the  Society  of  Arts.  The  constituents  are  28 
pounds  block-tin,  3.5  pounds  lead,  7  pounds  spelter,  and  14 
pounds  phosphor-tin.  The  phosphor-tin  should  contain  10  per 
cent  phosphor.  The  following  instructions  should  be  followed 
when  soldering  aluminum :  Clean  off  all  dirt  and  grease  from  the 
surface  of  the  metal  with  benzine,  apply  the  solder  with  a  copper 
bit,  and  when  the  molten  solder  covers  the  surface  of  the  metal, 
scratch  through  the  solder  with  a  wire  brush,  by  which  means  the 
oxide  is  broken  and  taken  up.  Quick  manipulation  is  neces- 
sary. 

Case-Hardening  u-ith  Kerosene. 

There  is  a  process  of  hardening  steel  by  petroleum  which  is 


198  HARDENING,    TEMPERING    AND    ANNEALING. 

not  generally  known.  The  article  to  be  treated  is  first  thorough!) 
rubbed  with  ordinary  washing  soap,  and  then  placed  in  a  char- 
coal fire  and  heated  to  a  cherry  red.  Then  it  is  plunged  into 
petroleum.  There  is  no  fear  of  the  oil  igniting,  but  it  is  wise 
not  to  have  a  naked  light  too  near.  Parts  hardened  by  this 
method  are  said  to  have  no  cracks  nor  do  they  warp,  and  after 
hardening,  owing  to  being  white,  can  be  finished  without  any 
cleaning  or  grinding. 

Case-Hardening  -Cones  and  Cups. 

For  case-hardening  small  pieces,  such  as  the  cups  and  cones 
used  in  bicycle  bearings,  the  following  method  has  been  found  to 
work  well  in  practice.  It  is  somewhat  different  from  the  usual 
plan  followed  by  case-hardeners  in  bicycle  factories :  First,  sur- 
round the  article  with  yellow  prussate  of  potash,  then  with  leather 
(old  boots  will  do),  then  with  clay,  and  pack  in  an  iron  box  of 
some  sort,  usually  a  piece  of  gas  pipe.  Plug  up  the  ends  with 
clay;  place  the  whole  in  the  fire  and  keep  at  a  red  heat  for  four 
or  five  hours,  then  quench  in  water.  The  usual  difficulty  with 
workers  in  a  small  way  is  to  keep  the  articles  at  a  uniform  tem- 
perature for  such  a  long  time. 

Drills. 

As  a  rule,  the  cutting  edges  of  twist  drills  are  formed  with 
a  cutter  of  correct  form  to  produce  a  radial  line  of  cutting  edge ; 
thus  a  different  form  of  cutter  is  required  for  milling  the  flutes 
of  straight  flute  drills. 

Drills  are  generally  made  of  .oo2-inch  or  .oo3~inch  taper  per 
foot  for  clearance  and  have  the  major  part  of  land  on  the  periph- 
ery ground  away  for  the  same  purpose,  about  .003  inch  on  a  side. 

Drills  for  brass  should  be  made  with  straight  flutes ;  those 
for  cast-iron  and  tool-steel  should  in  most  cases  have  spiral  flutes, 
at  an  angle  of  about  16  deg. ;  soft  steel,  22  deg. 

Chucking  drills,  for  use  on  cored  holes,  or  as  followers  of 
solid  twist  drills,  are  quite  often  provided  with  from  three  to 
eight  flutes ;  the  latter,  on  large  work,  are  very  efficient.  Care 
should  be  taken  in  grinding,  to  insure  all  teeth  cutting  simultan- 
eously. These  tools  are  made  of  solid,  shell,  and  inserted  type. 

The  inserted  type  are  preferable  for  straight  flutes  over  2%. 
inches,  and  for  angular  flutes  over  4  inches,  on  account  of  cost. 

For  drilling  a  large  hole  in  a  spindle  the  latter  should  be  sup- 


MISCELLANEOUS    METHODS,  TABLES,  ETC.  199 

ported  in  a  back  rest,  and  the  drill  entered  through  a  drill  bush- 
ing to  start  perfectly  true.  Then,  by  using  a  drill  with  one  cut- 
ting edge  and  ground  on  the  outside,  a  long,  straight  hole  may 
be  readily  produced.  An  ordinary  twist  drill  will  do  practically 
the  same  if  the  center  is  made  female,  the  only  objection  being 
that  this  form  is  much  more  difficult  to  grind. 

Reamer  Practice. 

.  The  following  particulars  in  regard  to  the  experience  of  the 
well  known  American  firm,  the  Lodge  &  Shipley  Machine  Com- 
pany, in  making  and  using  reamers,  were  given  by  their  Mr. 
William  Lodge: 

The  only  reamer  we  use  that  is  out  of  the  ordinary  is  a  taper 
reamer  made  with  only  three  blades.  These  are  cut  as  deep  as  the 
strength  of  the  stock  will  permit  and  have  very  little  clearance, 
which  is  obtained  by  grinding  the  blades  convex — not  flat  or  hol- 
low— as  shown  in  Fig.  141.  The  reamer  is  used  where  a  consider- 


FIG.   141. — TAPER   REAMER  WITH   THREE   BLADES. 

able  amount  of  metal  is  to  be  removed.  For  instance,  we  would 
bore  a  hole  of  the  right  size  for  the  small  end  of  the  reamer  and 
then  move  it  up  so  that  it  would  cut  a  length  anywhere  from  three 
to  six  inches,  feeding  very  rapidly.  We  have  bored  thousands  of 
holes  with  this  style  of  reamer,  getting  the  best  results  we  ever 
obtained  with  the  least  trouble  and  in  the  quickest  time. 

Many  reamers  are  -in  use  that  are  known  as  "home-made/' 
that  is,  made  by  the  parties  themselves.  We  have  found  a  great 
mistake  in  such  reamers.  It  often  occurs  that  the  flutes  are  cut 
too  shallow  and  the  spacing  is  entirely  too  close;  that  they  are 
evenly  spaced  instead  of  staggered,  and  very  often  have  an  even 
number  of  teeth,  all  of  which  is  likely  to  cause  chattering  and 
breaking  of  taper  reamers.  An  evenly  spaced  reamer  will  begin  to 
chatter  the  moment  the  cutting  edge  refuses  to  cut,  especially 


200 


HARDENING,    TEMPERING    AND   ANNEALING. 


when  cutting  steel  and  when  evenly  spaced,  one  blade  will  jump 
into  the  space  or  chatter  mark  made  by  the  blade  in  advance  of  it. 
Another  serious  fault  with  any  reamer,  either  straight  or  taper, 
is  too  much  clearance.  This  will  invariably  cause  a  reamer  to 
chatter. 

As  to. reamers  for  brass,  we  never  make  them  oversize,  and 
we  always  make  the  blade  of  the  reamer  for  brass  the  sa'me  as 
we  would  grind  a  tool  for  cutting  brass,  namely,  instead  of  using 
a  radial  line  on  the  center  as  in  other  cutting  tools,  we  throw  the 
cutting  edge  of  the  blade  off  from  the  center  at  an  angle  of  at 
least  20  degrees  out  of  the  radial  line,  as  shown  in  Fig.  142.  Thus, 
in  turning  brass,  if  you  had  a  tool  that  was  ground  straight  and 
mounted  it  in  the  tool  post  exactly  at  the  center  of  the  work  you 
would  find  that  the  tool  would  chatter.  Take  the  same  tool  and 


FIG.    142. — REAMER   FOR   BRASS. 


grind  it  on  the  top  to  an  angle  as  above  described  and  toward  tiie 
underside  of  the  blade,  and  it  would  cut  quite  freely  and  without 
any  chattering.  At  all  times,  however,  it  is  necessary  to  keep  the 
cutting  edge  of  the  reamer  for  brass  extremely  sharp,  because 
the  very  moment  the  cutting  edge  is  dull  it  will  begin  to  bind  and 
scream  sufficiently  loud  to  drive  you  out  of  the  shop.  Reamers 
for  reaming  brass  require  twice  or  three  times  the  attention  in 
keeping  to  a  sharp  edge  that  other  reamers  require. 

For  hand  reaming  we  never  have  to  exceed  3-1000  in  any 
material,  and  all  our  machine  reaming  is 'done  by  a  reamer  with 
very  much  coarser  blades  than  the  ordinary  commercial  reamer. 
They  are  made  so  that  they  may  be  ground  on  the  points,  are  fed 
rapidly,  and  the  tool  used  in  advance  of  them  leaves  in  no  case  less 
than  1-32  and  often  as  much  as  1-16. 

Reamers  and  Reaming. 
In  order  to  ream  uniform  holes   (as  regards  diameter)    in  a 


MISCELLANEOUS    METHODS,  TABLES,  ETC.  2OI 

screw  machine,  it  is  necessary  to  always  have  an  equal  amount  of 
stock  for  the  reamer  to  remove.  This  can  be  best  accomplished 
by  using  two  reamers,  one  for  roughing,  and  one  for  finishing. 
The  roughing  reamer  should  be  preceded  by  a  single  pointed 
boring  tool  (or  its  equivalent),  to  insure  a  true  hole.  On  thin 
work  a  finishing  reamer  should  be  of  "rose  form,"  so  as  to  be 
self-supporting  and  prevent  enlargement  of  the  hole  by  its  weight. 

For  steel,  reamers  are  ground  straight,  while  for  cast-iron, 
brass  and  copper  it  often  becomes  necessary  to  grind  same  slight- 
ly back  tapering  to  prevent  roughing  up. 

The  teeth  on  reamers  for  steel  and  cast-iron  should  be  on 
center,  while  for  brass  they  should  be  slightly  ahead  of  the  cen- 
ter. 

On  machine  reaming,  when  possible  to  do  so,  the  reamers  are 
hung  loose  and  allowed  to  follow  the  true  or  concentric  hole  made 
by  a  single-pointed  boring  tool.  This  can  be  done  by  having  a 
"floating"  reamer  with  a  pin  entered  through  the  holder  and  the 
reamer  at  the  back  end,  the  hole  in  the  reamer  being  larger  than 
the  pin  so  as  to  allow  it  to  find  its  own  center. 

Square  reamers  (scrapers)  are  often  used  for  fine  finishing, 
especially  on  brass.  Expansion  reamers  possess  many  desir- 
able features ;  but  there  are  few,  if  any,  that  can  be  adjusted  and 
used  for  sizing,  without  grinding  the  cutting  edges  each  time 
they  are  expanded,  as  unless  perfectly  fitted  in  as  regards  tapers, 
etc.,  the  separate  teeth  do  not  expand  equally. 

As  a  matter  of  cost,  however,  this  additional  grinding  amounts 
to  but  little  in  comparison  with  that  of  a  new  solid  or  shell 
reamer  of  large  diameter,  two  and  a  fourth  inches  or  more. 

Number  of  Teeth  Generally  Milled  in  Reamers. 

3-16  to  ^s  inch  diameter,  6  teeth. 
y%  to  il/4  inches  diameter,  8  teeth. 
il/4  to  \y2  inches  diameter,  10  teeth. 
il/2  to  2^  inches  diameter,  12  teeth. 
2%  to  3  inches  diameter,  14  teeth. 

3  to  4  inches  diameter,  16  teeth. 

4  to  5  inches  diameter,  18  teeth. 

A  long  hole  can  be  reamed  straight  by  pulling  back  slightly 
after  the  reamer  has  commenced  to  cut. 

Oh  Babbitt,  reamers  of  the  usual  form  are  used,  with  the  ex- 
ception that  the  point  is  ground  tapering  about  1/2 -inch  long,  to 


2O2  HARDENING,    TEMPERING    AND    ANNEALING. 

a  diameter  equal  to  size  generated  by  boring  tool.  This  gives  a 
smooth  hole,  free  from  lines,  also  prevents  rings.  Left-hand 
spiral  flutes  are  recommended. 

On  taper  reamers  for  screw  machine,  use  2j4  inches  per  foot 
and  upward.  They  will  cut  much  easier  if  made  with  left-hand 
spiral  flutes  or  angle,  but  on  account  of  difficulty  in  grinding  this 
is  not  often  done. 

For  forming  or  curving  reamers  for  projectile  work,  the  above 
holds  good.  Reamers  il/2  to  2^  inches  taper  per  foot  should 
have  flute  straight  for  finishers,  the  roughers  either  of  the  deep 
form  or  with  a  left-hand  spiral  thread  nicked  around.  The  ream- 
ers to  il/2  inches  taper  per  foot  are  fluted  left-hand  to  prevent 
drawing  in  when  cutting. 

Roughing,  taper  and  forming  reamers  are  sometimes  made 
from  steel  with  an  undercut,  and  also  with  right-hand  spiral,  and 
they  remove  the  stock  very  rapidly. 

Speeds  for  reaming  should  range  from  20  to  30  per  cent  less 
than  turning  and  drilling  speeds.  (See  tables,  pages  123  and 
124.) 

On  large  taper  reamers,  with  slight  taper,  it  has  been  found 
good  practice  to  make  each  tooth  a  different  left-hand  spiral  and 
also  to  "stagger"  the  teeth  as  regards  spacing. 

Rose  reamers  are  quite  often  ground  tapering,  that  is,  small 
at  back,  .003  to  foot,  and  then  are  less  liable  to  rough  up  the  hole 
they  are  reaming,  and  give  a  straight  hole  very  nearly  correct  in 
diameter. 

Grinding  Twist  Drills. 

Grinding  twist  drills  accurately  is  generally  admitted  to  be 
difficult.  To  know  the  number  of  revolutions  a  drill  should  run 
is  of  great  importance  in  order  to  obtain  the  most  economical  re- 
sults. The  illustration,  Fig.  143,  shows  opposite  sides  of  the 
Standard  Twist  Drill  Grinding  Gage,  made  of  steel  i-i6-inch 
thick.  The  angle  of  the  gage  is  ground  to  exactly  59  degrees. 
The  scale  on  the  gage  is  graduated  so  that  the  cutting  edges  of 
the  drill  can  be  measured  and  ground  exactly  the  same  length. 
The  straight  edge  of  the  gage  is  a  2-inch  scale  graduated  by 
eighths  of  an  inch  ;  opposite  each  eighth  mark  is  a  number,  which 
is  the  best  speed  to  run  a  drill  of  corresponding  size  of  diameter. 

In  using  the  gage,  hold  it  with  the  left  hand  and  place  the 
drill  in  the  gage  with  the  cutting  edges  of  the  drill  facing  you. 
The  rest  of  the  lip  of  the  drill  must  be  lower  than  the  cutting 
edge,  which  will  give  the  drill  clearance  and  allow  the  edges  to 


MISCELLANEOUS    METHODS,  TABLES,  ETC. 


203 


cut.  Always  keep  Twist  Drills  sliarp  and  run  them  at  the  proper 
speed.  If  you  want  to  force  a  drill  to  do  work  quickly,  run  at 
the  right  speed,  but  increase  the  feed. 

Circular  Forming  Tools. 

Circular  forming  tools  for  machine  steel  and  cast-iron  should 
have  a  generous  amount  of  clearance. 

Care  must  be  taken'  on  particular  forms,  when  forming  cutters 
are  not  on  center,  that  they  are  formed  with  this  point  taken 
into  consideration. 

Forming  cutters  with  steps  having  great  difference  of  diam- 


"3       46 


Opposite  sides  of  standard 
twist  drill  grinding  gauge 


/ 

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C  Iron 

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320 

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220 

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;  80 

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-  62 

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- 

58 
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o 

/ 

PIG.   143. 

•eter,  and  also  with  sharp  corners,  if  made  in  sections,  harden 
more  easily  and  safely. 

Circular  threading  tools  for  inside  threading  must  be  much 
smaller  than  the  work ;  about  one-third  is  the  proper  practice. 

Care  should  be  exercised  to  use  a  correct  angle  of  chaser. 

Plain  Forming   Tools. 

Plain  forming  tools  should  have  a  clearance  of  from  6l/2  to  IO 
degrees. 


2O4  HARDENING,    TEMPERING    AND   ANNEALING. 

Rake:  Machinery  steel  8  to  13  degrees. 

Rake  :  Tool  steel,  medium,  6  to  9  degrees. 

Rake :  Brass,  none. 

The  clearance  on  tools  for  brass  is  quite  often  stoned  off  its 
cutting  edge  to  prevent  "biting  in"  (due  to  ease  of  cutting)  and 
then  chattering,  due  to  great  thickness  of  chip  and  consequent 
difficulty  in  severing.  The  ''stoning  off"  also  tends  to  act  as  a 
support  for  the  cutter. 

Facing. 

For  steel  and  cast-iron,  cutters  with  from  6  to  12  degrees  rake 
cut  very  freely.  *The  clearance  should  be  from  3^2  to  10  degrees; 
when  there  is  any  tendency  to  chatter,  the  cutting  edge  should  be 
stoned  on  clearance  face  sufficiently  to  prevent  "biting  in."  On 
very  broad  work  it  often  becomes  necessary  to  make  cutters  with- 
out any  rake  or  angle,  but  allow  scraping,  to  prevent  chatter. 

In  practice  it  is  found  advantageous  to  place  cutter  ahead  of 
center,  exposing  a  larger  cutting  edge  to  work,  giving  thinner 
chip. 

In  multiple  or  inserted  cutter  heads,  it  is  well  to  unevenly 
space  the  cutters ;  as  a  precaution  against  chattering,  have  the  cut- 
ters "staggered." 

Use  machines  with  large  bearings,  and  with  chucks  close  to 
same,  for  good  results. 

Lubricant  in  Milling  Steel  or  Wrought  Iron. 

In  milling  steel  or  wrought  iron,  keep  cutter  thoroughly  wet 
with  lubricant.  Sal  soda  dissolved  in  water  is  often  used.  A 
better  lubricant  for  milling  cutter,  drill,  etc.,  is :  Lard  oil,  ^ 
gallon;  whale  oil  soap,  2  pounds;  sal  soda,  3  pounds;  water,  10 
gallons.  Have  the  soap  so  it  will  dissolve  readily.  Boil  the  whole 
until  dissolved. 

Cou  nterb  oring. 

For  cast-iron  and  steel,  counterbores  are  generally  made  with 
ten  to  sixteen  degrees  angle,  i.  e.,  spiral ;  for  brass  they  are  cut 
straight.  Clearance  is  from  five  to  ten  degrees.  On  brass, 
"stone"  the  clearance  edge  to  prevent  chattering. 

Counterbores  internally  lubricated  are  recommended  for  steel 
for  use  to  depth  of  one-half  of  the  diameter  or  more. 

Angle  clearance  on  all  tools  must  be  more  than  spiral  gen- 
erated by  feed,  at  smallest  diameter  of  cutting  point  plus  suffi- 
cient to  be  really  forced  in  work  (about  3  degrees ). 


MISCELLANEOUS    METHODS,  TABLES,  ETC. 


20  = 


Soldering. 

There  are  many  kinds  of-  solders,  from  that  which  will  melt 
in  boiling  water  to  hard  brass  solder  that  melts  only  at  white 
heat.  As  a  rule,  the  harder  the  solder  the  stronger  the  joint.  Of 
the  white  solders  silver  is  the  hardest.  For  all  solders  that  require 
a  red  heat,  borax  is  used  as  a  flux,  and  the  solder  will  run  anywhere 
the  borax  goes.  Rubbing  the  joint  with  a  pointed  piece  of  iron  will 
help  the  solder  to  run  into  the  joint.  The  parts  to  be  soldered 
should,  of  course,  be  cleaned.  The  solder  will  not  stick  to  the 
work  until  the  surface  of  the  work  is  heated  to  the  melting  point 
of  the  solder.  Don't  try  to  solder  with  a  cold  iron,  and,  with 


FIG.  144. — COUNTERBORE. 


FIG.    145. — COUNTERSINK. 

large  pieces,  heat  them  to  the  melting  point  of  the  solder  or  use 
a  very  hot  iron.  Always  use  a  solder  with  a  much  lower  melting 
point  than  that  of  the  metal  to  be  soldered. 

Useful  Information. 

Doubling  the  diameter  of  a  pipe  increases  its  capacity  four 
times. 

A  cubic  foot  of  water  weighs  62^/2  pounds,  and  contains  1,728 
cubic  inches,  or  jl/2  gallons. 

A  gallon  of  fresh  water  weighs  81-3  pounds,  and  contains  231 
cubic  inches. 

To  find  the  capacity  of  a  cylinder  in  gallons :  Multiply  the 
area  in  inches  by  the  height  of  stroke  in  inches.  Divide  this  prod- 
uct by  231  (being  the  cubical  contents  of  a  gallon  in  inches)  ; 
the  quotient  is  the  capacity  in  gallons. 


2O6  HARDENING,    TEMPERING    AND    ANNEALING. 

To  find  the  area  of  a  circle  or  cylinder :  Square  the  diameter 
in  inches  and  multiply  the  product  by  .7854. 

Example :    What  is  the  area  of  a  1 2-inch  circle  ? 

12X1 2=144+. 7854=1 1 3. 0976  square  inches. 

Rust  joint  cement  (quick  setting)  :  i  part  sal-ammoniac  in 
powder  (by  weight),  2  flour  of  sulphur,  80  iron  borings,  made  to 
a  paste  with  water. 

Rust  joint  (slow  setting)  :  2  parts  sal-ammoniac,  i  flour  of 
sulphur,  200  iron  borings. 

The  latter  is  best  if  joint  is  not  required  for  immediate  use. 

Metal  to  expand  in  cooling :  9  parts  lead,  2  antimony,  i  bis- 
muth. 

Glue  to  resist  moisture :  i  pound  of  glue  in  2  quarts  of 
skimmed  milk. 

To  color  or  coat  zinc :  Dissolve  i  ounce  blue  vitriol  in  4  ounces 
water,  add  teaspoonful  nitric  acid.  Apply  with  cloth. 

Lacquer  for  Brass  Articles. 

A  good  lacquer  for  brass  articles  is  made  from  best  orange 
shellac  dissolved  in  a  good  alcohol  (i  to  2  ounces  gum  to  the 
pint)  and  filtered  through  filter  paper.  This  is  excellent  for  brass, 
and  for  silver  the  bleached  shellac  may  be  substituted.  Some  pre- 
fer to  use  the  lacquer  thin  and  the  work  heated  to  about  115 
degrees  Fahr.,  a  temperature  that  will  vaporize  the  alcohol  and 
leave  a  firmly  adhering  coat  of  gum  if  the  work  has  been  prop- 
erly cleansed. 

Removing  Rust  from  Polished  Steel  and  Iron. 

In  the  Journal  of  the  United  States  Artillery  directions  were 
given  for  caring  for  ordnance,  and  the  treatment  recommended 
for  rust  on  polished  steel  is  as  follows :  Cyanide  of  potash  is 
most  excellent  for  removing  rust,  and  should  be  made  much  use 
of.  Instruments  of  polished  steel  may  be  cleaned  as  follows : 
First  soak,  if  possible,  in  a  solution  of  cyanide  of  potassium  in 
the  proportion  of  one  ounce  of  cyanide  to  four  ounces  of  water. 
Allow  this  to  act  till  all  loose  rust  and  scale  is  removed  and  then 
polish  with  cyanide  soap. 

The  cyanide  soap  referred  to  is  made  as  follows :  Potassium 
cyanide,  precipitated  chalk,  white  Castile  soap.  Make  a  saturated 
solution  of  the  cyanide  and  add  chalk  sufficient  to  make  a  creamy 
paste.  Add  the  soap  cut  in  fine  shavings  and  thoroughly  in- 


MISCELLANEOUS    METHODS,  TABLES,  ETC.  2O/ 

corporate  in  a  mortar.  When  the  mixture  is  stiff  cease  to  add 
soap.  It  may  be  well  to  state  that  potassium  cyanide  is  a  violent 
poison. 

For  removing  rust  from  iron  the  following  is  given  :  Iron  may 
be  quickly  and  easily  cleaned  by  dipping  in  or  washing  with  nitric 
acid,  one  part ;  muriatic  acid,  one  part ;  water,  twelve  parts. 
After  using  wash  with  clean  water. 

Miscellaneous  Information. 

Area  of  a  circle  =  diameter  X  -7854. 

Circumference  of  a  circle  =  diameter  X  3-I4I6. 

Given  the  area  of  a  circle  to  find  the  diameter,  divide  the  area 
by  .7854  and  extract  the  square  root. 

Area  of  a  hexagon  ==  length  of  one  side  X  2.598. 

Cubic  contents  in  inches  of  a  bar  of  iron  =  area  of  one  end  in 
inches  by  its  length,  in  inches. 

Weight  of  cast  iron,  per  cubic  inch,  .26  pound ;  of  wrought 
iron,  .278 ;  of  steel,  .283  ;  of  copper  and  bronze,  .32  ;  of  brass,  .3. 

A  wrought-iron  bar  one  square  inch  in  section  and  one  yard 
long  weighs  10  pounds.  Steel  is  about  two  per  cent  heavier  than 
wrought  iron.  Cast  iron  is  about  six  per  cent  lighter  than  wrought 
iron. 

To  find  the  surface  speed  in  feet  per  minute  of  an  emery 
wheel  or  milling  cutter :  Divide  the  number  of  revolutions  of  the 
wheel  per  minute  by  12,  and  multiply  the  result  by  3.1416  times 
the  diameter  of  the  emery  wheel  in  inches. 

To  find  the  number  of  revolutions  a  wheel  must  run  for  a 
given  surface  speed,  multiply  the  surface  speed  in  feet  per  min- 
ute by  12  and  divide  the  result  by  3.1416  times  the  diameter  in 
inches. 

Given,  the  diameter  of  a  hexagon  nut  across  the  flats,  to 
find  the  diameter  across  corners,  multiply  the  diameter  across 
flats  by  1.156. 


208 


HARDENING,    TEMPERING    AM)   ANNEALING. 


TABLE     OF      DECIMAL      EQUIVALENTS      OF      MILLIMETERS      AND 
FRACTIONS    OF    MILLIMETERS. 

ITJ-Q  nim.  ^  .0003937  inch. 


MM 

Indies 

MM 

Inches 

MM 

Inches 

s'o 

.00079 

H 

.02047 

2 

.07874 

& 

.00157 

H 

.02126 

3 

.IlSlI 

A 

.00236 

M 

.02205 

4 

•'5748 

54<J 

•00315 

1* 

.02283 

5 

.19685 

& 

.00394 

H 

.02362 

6 

.23622 

3% 

.00472 

H 

.02441 

7 

•2/559 

/O 

•00551 

II 

.02520 

8 

.31496 

5% 

.00630 

n 

.02598 

9 

•35433 

A 

.00709 

u 

.02677 

10 

•39370 

H 

.00787 

H 

•02756 

ri 

•43307 

W 

.00866 

H 

•02835 

12 

•47244 

H 

•00945 

H 

.02913 

"3 

.51181 

i! 

.01024 

If 

.02992 

M 

•55IJ8 

it 

.OIIO2 

H 

.03071 

15 

•59055 

M 

•OflSl 

!§ 

•03150 

16 

.62992 

sf 

.01200 

ft 

•03228 

17 

.66929 

it 

•01339 

H 

•03307 

18 

.70866 

H 

.01417 

H 

.03386 

19 

.74803 

H 

.01496 

H 

•03465 

20 

.78740 

H 

•01575 

If 

•03543 

21 

.82677 

n 

.01654 

H 

.03622 

22 

.86614 

H 

.01732 

It 

.03701 

23 

•90551 

n 

.Ol8ll 

f$ 

.03780 

24 

.94488 

i$ 

.01890 

H 

.03858 

*25 

.98425 

it 

.01969 

1 

•03937 

26 

1.02362 

10  mm. 
10  cm. 
10  dm. 
25.4  mm. 


:  i  centimeter  =  0.3937  inches. 

:  i  decimeter    =  3.937  inches. 

=  i  meter         =  39.37  inches. 
=  i  English  inch. 


MISCELLANEOUS    METHODS,  TABLES,  ETC. 


209 


DECIMAL   EQUIVALENTS   OF    PARTS    OF   AN    INCH. 


A  .01563 

H  .32813 

Jf  .70318 

A    .03125 

44    .34375 

§i    .71875 

•ft  .04688 

H  .35938 

JJ  .73430 

/ii     «°625 

%      .375 

%      '75 

/4-  .07813 

If  .39063 

fj  .76563 

3%    .09375 

if    .40625 

If    .78125 

A  .10938 

Ji  .42188 

44  -79688 

X      .125 

Xe      *4375 

%     -8125 

&  .14063 

1!  .45313 

4f  .82813 

A    .15625 

^    .46875 

§£    .84375 

44  .17188 

44  .48438 

44  .85938 

%>      .1875 

YT,       -5 

x   -875 

43  .20313 

•Ji  .51563 

4}  .89063 

A    .2*875 

4J    .53125 

5S-    .90625 

4$  .23438 

jf  .54688 

4J  .92188 

%      ,25 

^6        -5625 

%      -9375 

4i  .26o63 

gj  .57813 

14  .95313 

A    .28125 

42    .59375 

H    .96875 

4f  .29688 

|J  ..60938 

41  .98438 

&     .3125 

X      .625 

1    i.ooooo 

J4  -64063 

§4    .65625 

H  .67188 

%      ,6875 

210 


HARDENING,    TEMPERING    AND    ANNEALING. 


CONSTANTS    FOR    FINDING    DIAMETER    AT    BOTTOM    OF    THREAD. 


Threads 
per  Inch. 

u.  s. 

Standard 
Constant. 

V  Thread 
Constant. 

Threads 
per  Inch. 

u.  s. 

Standard 
Constant. 

V  Thread 
Constant. 

64 

.02029 

.02706 

16 

.08118 

.  10825 

60 

.02165 

.02887 

14 

.09278 

.  12357 

56 

.02319 

.03093 

13 

.09992 

.  13323 

50 

^02598 

.03464 

12 

.  10825 

.14433 

48 

.02706 

.03608 

11 

.11809 

.  15745 

44 

.02952 

.03936 

10 

.12990 

.17320 

40 

.0324? 

.04330 

•9 

.  14433 

.19244 

86 

.03608 

.04811 

8 

.  16237 

.21650 

82 

.0405$ 

05412 

7 

.18555 

.24742 

30 

,04330 

.05778 

6 

.21650 

.28866 

28 

.04639 

.06185 

5^ 

.23618 

.31490 

26 

.04996 

06661 

5 

.25980 

.34650 

24 

.05412 

072  f  6 

W 

.28866 

.38488 

22 

.05904 

.07872 

4 

.32475 

.43300 

20 

06495 

.08660 

3K 

.37114 

.49485 

18 

07216 

09622 

3 

43333 

.57733 

C  =  Constant  for  number-  of  threads  per  inch. 

D  =  Outside  diameter. 

D1—  Diameter  at  bottom  of  thread. 


EXAMPLE.  —  Given  outside  diameter  of  U.  S.  S.  screw 
thread,  2  inches,  4%  threads  per  inch;  find  diameter  at 
bottom  of  thread.  D  =  2  inches;  for  4%  threads  U.  S. 
S.  constant,  C  =  .2886  ;  then  diameter  at  bottom  of  thread 
D*  =  2  —  .2886=1.7114  inches. 


MISCELLANEOUS    METHODS,  TABLES,  ETC. 


211 


METRIC    AND    ENGLISH    OR    AMERICAN     (U.    S.)     EQUIVALENT 
MEASURES. 


(  $».37  inches. 
I  meter  =  ]   3.28083  feet. 

(   1.0936yds. 
1  centimeter  =  .3937  inch. 


Measures  of  Length. 


foot 


.3048  meter. 
(  2.54  centimeters* 
:{25.4   millimeters. 

1  kilometer  =  0.62137  mile. 

Measures  of  Surface. 

1  square  meter  =  J  10  764  square  feet.  Jl  square  yard  =  .836   square  meter. 

I    1.196  square  yds.  il  square  foot  =  .0929  square  meter. 

1  square  centimeter  =   155  s:j.  in. 

1  square  millimeter  —  .00155  sq.  in 


Measures  of  Volume  and  Capacity 
f  35  314  cubic  feet. 
1  cubic  meter  =  <     1 .308  cubic  yards. 
(264.2     gallons     (231 


cubic  inch). 


1  cubic  centimeter  =  .061  cubic  inch. 
1  cubic  decimeter. 
61.023  cubic  inches. 

0353  cubic  foot. 
1.0567  quarts  (U.  S.) 

2642  gallons  (U.  S.)    . 
2.202   lbs.ofwaterat62°F. 


1  liter 


1  cubic  yard  =  .7643  cubic  meter. 


1  cubic  ft. . 


f     .02832 cubic  meter. 

^28.317 


cubic  decimeters 
1 28.317    liters. 
1  cubic  inch  =*  16  387  cubic  centimeters. 
1  gallon  (British)  =  4  543  liters. 
1  gallon  (U.  S.)  *»  3.785  liters. 


1  gram  =  15.432  grains. 

1  kilogram  =  2.2046  pounds. 

( .9842  ton  of  2240  Ibs. 
1  metric  ton  =  <     19.68  cwts. 

1 2204.6  Ibs. 


Measures  of  Weight. 

1  grain  =  .0648  gram. 

1  ounce  avoirdupois  =  28.35  grams 

1  pound  =  .4536  kilograms. 


1  ton  of  2240  Ibs.  =  j  liS,«l£?,trlctolia' 
/    1016  kilograms. 


MlsceUaneous. 

1  kilogram  per  meter  =  .6720  pounds  per  foot. 
1  gram  per  square  millimeter  =  1.422  pounds  per  square  inch. 
1  kilogram  per  square  meter  =•       0.2084  •»      foot 

1  kilogram  per  cubic  meter  =         .0624       "       cubic      " 

1  degree  centigrade  =  1.8  degrees  Fahrenheit. 
1  pound  per  foot  =  1.488  kilograms  per  meter. 
1  pound  per  square  foot  =  4.882  kilograms  per  square  meter. 
'  '    "act  =  ltt.02  kilograms  per  cubi 


I  pound  per  cubic  foot  =  16.02  kilograms  pe 

1  degree  Fahrenheit  =  .5556  degrees  centigrade. 


ic  meter. 


1  Calorie  (French  Thermal  Unit)  =  3.968  B.  T.  U.  (British  Thermal  Unit) 

1  Horse  Power  =  j  ijg^gj  **un**  pcr  minule' 
1  Watt  (Unit  of  Electrical  Power)  =  {44  P^134  5°™  Power' 

f  1000  Watts. 
1  Kilowatt  =<  1.34  Horse  Power 

(44240  foot  pounds  per  minute. 


212 


HARDENING,    TEMPERING   AND   ANNEALING. 


WEIGHTS     AND     AREAS     OF    ROUND,     SQUARE     AND     HEXAGON 
STEEL. 

Weight  of  one  cubic  inch  =  .2836  Ibs. 
Weight  of  one  cubic  foot  =  490  Ibs. 


Area  =  Diam.2  x  .7854. 


Area  =  Side2  x  1. 


rea  =  Diam.2x.866 


Round. 


Square. 


Hexagon. 


Weight 
Per 

Inch. 


Area 
Square 
Inches. 


Circum- 
ference 
Inches. 


Weight 

Per 

Inch. 


Area 
Square 
Inches. 


Weight 

Per 

Inch. 


Area 
Square 
Inches. 


.0002 
.0009 
.0020 
.0035 

.0054 
.0078 
.0107 
.0139 

.0176 
.0218 
.0263 


.0008 
.0031 


.0123 


.0276 
.0376 
.0491 

.0621 
.0767 


,,., 

.0557 


.1104 

.1296 
.1503 
.1726 


.0705 
.0785 
.0370 


.1053 
.1151 
.1253 


.1470 
.1586 
,1705 

,1829 
.1958 
.2090 
.2227 

.2515 
.2819 
.3141 
.3480 

.3837 
.4211 
.4603 
.5012 

.5438 


.2217 
.2485 
.2769 


.8712 
.4057 
.4418 

.4794 
.5185 
.5591 
.6013 

.6450 

.6903 
.7371 
.7854 


1.1075 
1.2272 

1.3530 
1.4849 


1.7671 

1.9175 
2.0739 


.1963 


.4908 
.5890 
.6872 
.7854 


.9817 
1.0799 
1.1781 

1.2762 
1.3744 
1.4726 
1.5708 


1.7671 


2.4053 


1.9635 

2.0616 
2.1598 
2.2580 
2.3562 

2.4543 
2.5525 
2.6507 
2.7489 

2.8470 
2.9452 
3.0434 
3.1416 

3.3379 
3.5343 
3.7306 
3.9270 

4.1233 
4.3197 
4.5160 
4.7124 

4.9087 
5.1051 
5.3014 
5.4978 


.0003 
.0011 
.0025 
.0044 


.0101 
.0136 
.0177 

.0224 
.0277 
.0335 
.0405 

.0466 
.0543 
.0623 
.0709 

.0800 
.0897 
.1036 
.1108 

1221 
.1340 
.1465 
.1622 

.1732 
.1872 
.2019 
J2171 


.0010 


.0156 

.0244 
.0352 
.0479 


.0791 
.0977 
.1182 
.1406 

.1651 
.1914 
.2197 
.2500 

.2822 
.3164 


.0002 
.0010 
.0022 
.0038 

.0060 
.0086 
.0118 
.0154 

.0194 
.0240 
.0290 
.0345 

.0405 
.0470 
.0510 
.0614 

.0693 
.0777 


.0008 
.«034 
.0076 
.0135 

.0211 
.0304 
.0414 
.0510 

.0686 
.0846 
.1023 
.1218 

.1428 
.1658 
.1903 
.2161 

.2444 

.2743 


.2492 
.2661 


.4142 
.4431 


.4307 
.4727 
.5166 
.5625 

.6103 
.6602 
.7119 
.7656 

.8213 

.8789 

.9384 

1.0000 

L1289. 
1.2656 
1.4102 
1.5625 

1.7227 


.5860 
.6487 


2.0664 
2.2500 

2.4414 
2.6406 
2.8477 
3.0625 


.1058 
.1161 
.1270 
.1382 

.1499 
.1620 
J749 
.1880 

.2015 
.2159 
.2305 
.2456 

.2773 
.3109 
.3464 


.4231 
.4643 
.5076 


.6480 
.6994 
.7521 


.3730 
.4093 
.4474 
.4871 


.5712 


.7112 
.7612 
.8127 
.8643 

.9776 
1.0973 
1.2212 
1.3531 


2X143 
2.2847 
2.4662 
2.6532 


MISCELLANEOUS    METHODS,  TABLES,  ETC. 


213 


WEIGHTS     AND    AREAS     OF     ROUND,     SQUARE     AND     HEXAGON 
STEEL. 

Continued. 


Thickness 
or  Diam. 

Round. 

Square. 

Hexagon. 

Weight 
Per 
Inch. 

Area 
Square 
Inches. 

Circum- 
ference 
Inches. 

Weight 
Per 
Inch. 

Area 

Square 
Inches. 

Weight 
Per 
Inch. 

Area 
Square 
Inches. 

111 
V 

.7317 
.7831 
.8361 
.8910 

2.5802 
2.7612 
2.9483 
3.1416 

5.6941 
5.8905 
6.0868 
6.2832 

.9316 
.9970 
1.0646 
1.1342 

3.2852 
3.5156 
3.7539 
4.0000 

.8069 
.8635 
.9220 
.9825 

2.8450 
3.0448 
3.250D 
3.4573 

IP, 

a 

.9475 

1.0058 
1.0658 
1.1276 

3.3410 

3.5466 
3.7583 
3.9761 

6.4795 

6.6759 
6.8722 
7.0686 

1.2064 
1.2806 
1.3570 
1.4357 

4.2539 

4.5156 
4.7852 
5.0625 

1.0448 
1.1091 
1.1753 
1.2434 

3.6340 
3.9106 
4.1440 
4.3892 

% 

% 

1.1911 

1.2564 
1.3234 
1.3921 

45000 
4.4301 
4.6664 
4.9087 

7.2649 
7.4613 
7.6575 
7.8540 

1.5165 

1.6569 
1.6849 
1.7724 

6.3477 

5.6406 
6.9414 
6.2500 

1.3135 
1.3854 
1.4593 
1.5351 

4.6312 
4.8849 
5.1454 
5.4126 

i% 

2% 

1.5348 

1.6845 
1.8411 
2.0046 

5.4119 

5.9396 
6.4918 
7.0686 

8.2467 
8.6394 
9.0321 
9.4248 

1.9541 
2.1446 
2.3441 
2,5548 

6.8906 
7.5625 
8.2656 
9.0000 

1.6924 
1.8574 
2.0304 
2.2105 

5.9674 
6.5493 
7.1590 
7.7941 

§' 

2.1752 
2.3527 
2.5371 
2.7286 

7.6699 
82958 
8.9462 
9.6211 

9.8175 
10.2102 
10.6029 
10.9956 

2.7719 
2.9954 
3.2303 
3.4740 

9.7656 
10.5625 
11.3906 
12.2500 

2.3986 
2.5918 
2.7977 
3.0083 

8.4573 

9.1387 
98646 
10.6089 

3% 

2.9269 
3.1323 
3.3446 
3.5638 

10.3206 
11.0447 
11.7932 
12.5664 

11.3883 
11.7810 
12.1737 
12.5664 

3.7265 

3.9880 
4.2582 
4.5374 

13.1407 

14.0625 
15.0156 
16.0000 

3.2275 
3.4539 
3.6880 
3.9298 

11.3798 

12.1785 
13.0035 
138292 

4'/8 

45i 
tH 

3.7900 
40232 
4.2634 
4.5105 

13.8640 
14.1863 
15.0332 
15.9043 

12.9591 
13.3518 
13.7445 
14.1372 

4.8254 
5.1223 
5.4280 
5.7426 

17.0156 
18.0625 
19.1406 
20.2500 

4.1792 

4.4364 
4.7011 
4.9736 

14.7359 
15  642t 
16.5761 
17.5569 

4V 

4.7645 
5.0255 
5.2935 
5.5685 

16.8002 
17.7205 
18.6655 
19.6350 

14.5299 
14.9226 
15.3153 
15.7080 

6.0662 
6j8276 
6.7397 
7.0897 

21.3906 

22.5625 
23.7656 
25.0000 

5.2538 
55416 
5.8371 
6.1403 

18.5249 
19.5397 
20.5816 
21.6503 

m 

% 

m 

5.8504 
6.1392 
6.4351 
6.7379 

20.6290 
21.6475 
22.6905 
23.7583 

16.1007 

16.4934 
16.8861 
17.2788 

7.4496 
7.8164 
8.1930 
8.5786 

26.2656 
27.5624 
28.8906 
30.2500 

6.4511 

6.7697 
7.0959 
7.4298 

22.7456 
23.8696 
25.0198 
26.1971 

| 

7.0476 

7.3643 
7.6880 
8.0186 

24.8505 
25.9672 
27.1085 
28.2743 

17.6715 
18.0642 
18.4569 
18.8496 

8.9729 
9.3762 
9.7883 
10.2192 

31.6406 
83.0625 
34.5156 
36XJOOO 

7.7713 
8.1214 

8.4774 
8.8420 

27.4013 
28.6361 
29.8913 
31.1765 

1 

8.7007 
9.4107 
10.1485 
10.9142 

30.6796 
33.1831 
86.7847 
88.4845 

19.6350 
20.4204 
21.2058 
21.9912 

11.0877 
11.9817 
12.9211 
13.8960 

39.0625 

42.2500 
45.5625 
49.0000 

9.5943 
10.3673 
11.1908 
12.0351 

33.8291 
36.5547 
39.4584 
42.4354 

^ 

12.5291 

4QB 

44.1786 
50.2655 

23.5620 
25.1328 

15.9520 
18.1497 

66.2500 
64.0000 

13.8158 
15.7192 

48.7142 
55.3169 

1 

Multiply  above  weights  by  .993  for  wrought  iron,  .918 
for  cast  iron,  1.0331  for  cast  brass,  1.1209  for  copper,  and 
1.1748  for  phos.  bronze. 


214 


HARDENING,    TEMPERING    AND    ANNEALING. 


WEIGHT  OF   IRON   AND   STEEL   SHEETS. 

Weights    per    Square    Foot. — Kent. 


Thickness  by 

Thickness  by  American 

Birmingham  Gauge. 

(Brown  and  Sharpe's)  Gauge. 

No.  of 
Gauge. 

Thickness 
in  Inches. 

Iron. 

Steel. 

No.  of 
Gauge. 

Thickness 
in  Inches. 

Iron. 

Steel. 

0000 

.454 

18.16 

18.52 

0000 

.46 

18.40 

18.77 

000 

.425 

17.00 

17/34 

000 

.4096 

16.38 

16:71 

00 

.38 

15020 

15.50 

00 

.3648 

14.59 

14.88 

0 

.34 

13.60 

13.87 

0 

.3249 

13.00 

13.26 

1 

.3 

12.00 

12.24 

1 

.2893 

11.57 

11.80 

2 

.284 

11.36 

11.59 

2 

.2576 

10.30 

10.51 

3 

.259 

10.36 

10.57 

3 

.2294 

9.18 

9.36 

4 

.238 

9.52 

9.71 

4 

.2043 

8.17 

8.34 

5 

.22 

8.80 

8.98 

5 

.1819 

7.28 

7.42 

6 

.203 

8.12 

8.28 

6 

.1620 

6.48 

6.61 

7 

.18 

7.20 

7.34 

7 

.1443 

5.77 

5.89 

8 

,165 

6.60 

6.73 

8 

.1285 

5.14 

5.24 

9 

.148 

5.92 

6.04 

9 

.1144 

4.58 

4.67 

10 

.134 

5.36 

5.47 

10 

.1019 

4.08 

4.16 

11 

.12 

4.80 

4.90 

11 

.0907 

3.63 

3.70 

12 

.109 

4.36 

4.45 

12 

.0808 

3.23 

3.30 

13 

.095 

3.80 

3.88 

13 

.0720 

2.88 

2.94 

14 

.083 

3.32 

3.39 

14 

.0641 

2.56 

2.62 

15 

.072 

2.88 

2.94 

15 

.0571 

2.28 

2.33 

16 

.065 

2.60 

2.65 

16 

.0508 

2.03 

2.07 

17 

.058 

2.32 

2.37 

17 

.0453 

1.81 

1.85 

18 

.049 

1.96 

2.00 

18 

.0403 

1.61 

1.64 

19 

.042 

1.68 

1.71 

19 

.0359 

1.44 

1.46 

20 

.035 

1.40 

1.43 

20 

.0320 

1.28 

1.31 

21 

.032 

1.28 

1.31 

21 

.0285 

1.14 

1.16 

22 

.028 

1.12 

1.14 

22 

.0253 

1.01 

1.03 

23 

.025 

1.00 

1.02 

23 

.0226 

.904 

.922 

24 

.022 

.88 

.898 

24 

.0201 

.804 

.820 

25 

.02 

.80 

.816 

25 

.0179 

.716 

.730 

26 

.018 

.72 

.734 

26 

.0159 

.636 

.649 

27 

.016 

.64 

.653 

27 

.0142 

.568 

.579 

28 

.014 

.56 

.571 

28 

.0126 

.504 

.514 

29 

.013 

.52 

.530 

29 

.0113 

.452 

.461 

30 

.012 

.48 

.490 

30 

.0100 

.400 

.408 

31 

.01 

.40 

.408 

31 

.0089 

.356 

.363 

32 

.009 

.36 

.367 

32 

.0080 

.320 

.326 

33 

.008 

.32 

.326 

33 

.0071 

.284 

.290 

34 

.007 

.28 

.286 

34 

.0063 

.252 

.257 

35 

.005 

.20 

.204 

35 

.0056 

.224 

.228 

Iron.  Steel 

Specific  gravity    7.7  7.854 

Weight  per  cubic   foot 480.  489.6 

Weight  per  cubic  inch 2778          .2833 

As  there  are  many  gauges  in  use  differing  from  each 
other,  and  even  the  thicknesses  of  a  certain  specified 
gauge,  as  the  Birmingham,  are  not  assumed  the  same  by 
all  manufacturers,  orders  for  sheets  and  wires  should  al- 
ways state  the  weights  per  square  foot,  or  the  thickness 
in  thousandths  of  an  inch. 


MISCELLANEOUS    METHODS,  TABLES,  ETC. 


215 


WEIGHTS  OF   SQUARE  AND  ROUND  BARS  OF  WROUGHT  IRON  IN 
POUNDS      PER     LINEAL     FOOT. — Kent. 

Iron  weighing  480  Ibs.  per  cubic  foot. 
For  steel  add  2  per  cent. 


•  Thickness 
or  Diameter 
in 
Inches 

Weight  of 
Square  Bar 
One  Foot 

Long. 

Weight  of 
Round  Bar 
One  Foot 
Long. 

Thickness 
or  Diameter 
in 
Inches. 

Weight  of 
Square  Bar 
One  Foot 
Long. 

Weight  <* 
Round  Bar 
OncBViot 
Lenfe* 

o 

2  11-16 

24.08 

18.91' 

1  16 

.013 

.010 

3-4 

25.21 

19.80 

1-8 

.052 

.041 

13:16 

26.37 

20.71 

3  10- 

.117 

.092 

7-8 

27.55 

-21.64 

1-4 

.208 

.164 

15-16 

28J6 

22.59 

5-16 

.326 

.256 

8 

30.00 

23.56 

38 

.469 

.368 

1-16 

31.26 

24.55 

7-16 

.638 

.501 

1-8 

82.55 

25.57 

1-2 

.833 

.654 

3-16 

33.87 

26.60 

9-16 

1.055 

.828 

14 

85.21 

27.65 

5-8 

1.302 

1.023 

5-16 

86.58 

28.7S 

11-16 

1.576 

1.237 

3-8 

37.97 

29.82. 

3-4 

1.875 

1.473 

7-16 

89.39 

30.94 

13  16 

2.201 

1.728 

1.2 

40.88 

82.07 

7-8 

2.552 

2.004 

0-16 

42.30 

83.23 

15  16 

2.930 

2.301 

5-8 

43.80 

3440 

\ 

3.333 

2.618 

11-16 

45.33 

35,60 

1-16 

3.763 

2.955 

3-4 

46.88 

36.82 

1-8 

4.219 

3.313 

13-16 

48.45 

38.05 

316 

4.701 

3.692 

7-8 

60.05 

39.31 

1-4 

5.208 

4.091 

15-16 

51.68 

40.59 

6-16 

5.742 

4.510 

4 

53.33 

41.80 

3-8 

6.302 

4.950 

1-16 

65.01 

43.21 

7-16 

6.888 

5.410 

1-8 

66.72 

44.55 

1.2 

7.500 

5.890 

346 

68.45 

45.91 

9-16 
5-8 

8.138 

8.802 

6i913 

M6 

60.21 
61.99 

47.29 
48.69 

11-16 

9.492 

7.455 

8-8 

63.80 

50.11 

34 

10.21 

8.018 

7-16 

65.64 

51.55 

1316 

10.95 

8.601 

1-2 

67.50 

63.01 

7-8 

11.72 

9.204 

9-16 

69.39 

64.50 

15-16 

12.51 

9.828 

6-8 

71.30 

66.00 

2 

13.33 

10.47 

11-16 

73.24 

67.52 

1  16 

14.18 

11.14 

84 

75.21 

59.07 

1-8 

15.05 

11.82 

18-16 

77.20 

60.68 

316 

15.95 

12.53 

7-8 

79.22 

62.22 

14 

16.88 

13.25 

10-16 

81.26 

63.82 

5-16 

17.83 

14.00 

5 

88.33 

65.45 

3-g 

18.80 

14.77 

M6 

85.43 

67.10 

716 

19.80 

15.55 

1.8 

87.55 

68.76 

12 

20.83 

16.36 

8-16 

89.70 

70.45 

0-16 

21.89 

17.19 

14 

91.88 

72.16 

5-8 

22.97 

18.04 

5-16 

94.08 

73.89 

216 


HARDENING,    TEMPERING   AND   ANNEALING. 


WEIGHTS  OF  SQUARE  AND  ROUND  BARS  OF  WROUGHT  IRON   IN 
POUNDS   PER  LINEAL   FOOT. — Kent. 

Iron  weighing  480  Ibs.  per  cubic  foot. 
For  steel  add  2  per  cent. 


Thickness 
pr  Diameter 
in  Inches. 

Weight  of 
Square    Bar 
One  Foot 

.Long. 

Weight  of 
Round    Bar 
One  Foot 
Long. 

Thickness 
or  Diameter 
in  Inches. 

Weight  of 
Square  Bar 
One  Foot- 
Long. 

Weight  of 
Round  Bar 
One  Foot 
Long. 

6   3-8 

96.30 

75.64 

7  1-2 

187.5 

147.3 

7-16 

98.55 

77.40 

5-8 

193.8 

152.2 

12 

100.8 

79.19 

3-4 

200.2 

157.2 

9-16 

103.1 

81.00 

7-8 

206.7 

162.4 

5-8 

105.5 

82.83 

8 

213.3 

167.6 

11-16 

107.8 

84.69 

1-4 

226.9 

178.2 

3-4 

110.2 

86.56 

1-2 

240.8 

189.2 

13-16 

112:6 

88.45 

3-4 

255.2 

200.4 

7-8 

115.1 

90.36 

9 

270.0 

212.1 

-  15-16 

117.5 

92.29 

1-4 

.285.2 

224.0 

6 

120.0 

94.25 

1-2 

300.8 

236,3 

1-8 

125.1 

98.22 

3-4 

316.9 

248.9 

!4 

130.2 

102.3 

10 

333.3 

261.8 

3-8 

135.5 

106.4 

1-4 

350.2 

275.1 

12 

140.8 

110.6 

1-2 

367.5 

288.6 

5-8 

146.3 

114.9 

3-4 

385.2 

302.5 

3-4 

151.9 

119.3 

11 

403.3 

316.8 

7-8 

157.6 

123.7 

1-4 

421.9 

331.3 

7 

163.3 

128& 

1-2 

440.8 

346.2 

1-8 

169.2 

132.9 

34 

460.2 

361.4 

1-4 

175.2 

137.6 

12 

480. 

377. 

3-8 

181.3 

142.4 

To  compute  the  Weight  of  Sheet  Steel: 
Divide  the  thickness,  expressed  in  thousandths,  by  25; 
the  result  is  the  weight,  in  pounds,  per  square  foot. 


MISCELLANEOUS    METHODS,  TABLES,  ETC.  2I/ 


UNITED    STATES    WEIGHTS    AND    MEASURES. 

Measures  of  Length. 

12  inches I    foot. 

3  feet i  yard. 

5^  yards  or  i6l/2  feet I  rod. 

40  rods  or  220  yards I  furlong. 

8  furlongs,  or  1760  yds.,  or  5,280  ft.  i  mile. 

Measures  of  Surface. 

144  square  inches i  square  foot. 

9  square    feet i  square  yard. 

30J4  sq.  yds.,  or  27254  sq.  ft..i  square  rod. 

160  sq.  rods,  or  4840  sq.  yards  i  acre. 

640  acres i  square  mile. 

Measures  of  Volume. 

1728  cubic  inches i  cubic  foot. 

27  cubic  feet i  cubic  yard. 

128  cubic  feet i  cord  wood. 

Measures  of  Weight. 

Commercial. 

437/^2  grains  (Troy) i  ounce  Avoirdupois. 

1 6  ounces  or  7000  grains i  pound  (Ib.)  Avoirdupois. 

100  pounds i  hundredweight   (cwt.) 

20  hundredweight  or  2000  Ibs  i  net  ton. 
2240  pounds i  gross  ton. 


218 


HARDENING,    TEMPERING   AND    ANNEALING. 


TAP  DRILLS   FOR   MACHINE   SCREW  TAPS. 

These  drills  will  give  a  thread  full  enough  for  all  prac- 
tical purposes,  but  not  a  full  thread. 


Sizes  of 
Taps 

No.  of 

Threads 

Sizes  ot 
Drills 

Sizes  of 
Taps 

No.  of 
Threads 

Sizes  of 
Drills 

2 

48 

48 

12 

24 

19 

2 
1 

56                     46 

64                 45 

\l 

20 
24 

17 
15 

3 

40 

48 

14 

20 

14 

3 

48 

47 

14 

22 

13 

3 

56 

45 

14 

24 

II 

4 

32 

45 

'5 

18 

12 

4 

36 

43 

'5 

20 

IO 

4 

40 

42 

1  5 

24 

7 

5 

3° 

41 

16 

16 

10 

5 

32 

40 

1         16 

18 

7 

*/ 

5 

36 

38 

16 

20 

5 

i 

40 
30 

36 
39 

16 

17 

24 

16 

7 

6 

32 

37 

17 

18 

4 

6 

36 

35 

17 

20 

2 

6 

40 

33 

j8 

16 

2 

7 

28 

32 

18 

18 

I 

/ 

7 
8 

30 
32 
24 

3' 

i        3° 
31 

18 

'9 
19 

20 

16 
18 

B 
C 
D 

8 
8 
9 

30 

32 
24 

30 
29 
29 

'9 

20 

!            20 

20 

16 
18 

E 
E 
E 

28 

27 

2O 

20 

F 

9 
9 
10 

30 
32 
24 

26 

24 
26 

22 
22 
24 

16 
18 

H 
I 

K 

10 

28 

24 

24 

16 

L 

10 
10 

1  1 

3° 
32 
24 

23 

21 

20 

24 
26 
26 

18 

14 

16 

M 
O 
P 

1  1 

2$ 

*9 

28 

14 

R 

II 

3° 

li 

28 

16 

S 

*? 

20 

21 

30 

'14 

T 

12 

22 

19 

16        |        U 

SIZE   OF   DRILLS   FOR    STANDARD   PIPE   TAPS. 


Nom'l 

Threads 

Diam. 

Nom'l 

Threads 

Diam 

Nom'l 

Threads 

Diam. 

Diam. 

per  inch 

of  Drill 

Diam. 

per  inch 

of  Drill 

Diam. 

per  inch 

of  Drill 

% 

27 

1 

l 

1A 

3 

8 

m 

/4 

18 

|| 

im 

Hi 

8 

3% 

ft 

18 
14 

|| 

2^ 

an 

if! 

4 

8   ' 
8 

m 

B 

14 

fl 

* 

8 

2% 

5 

8 

6A 

MISCELLANEOUS    METHODS,  TABLES,  ETC. 


219 


DIFFERENT  STANDARDS  FOR  WIRE  GAGE  IN  USE  IN  THE  UNITED 
STATES. 

Dimensions  of  Sizes  in  Decimal  Parts  of  an  Inch 


"••*  Q> 
0  bo 

fel 

J=O 

§£ 

*5 

American 
or  Brown  & 
Sharpe. 

Birmingham, 
or 
Stubs'  Wire. 

Washburn  & 
MoenMfgCo., 
Worcester,Ms. 

Imperial 
Wire  Gauge 

g 

l! 
»l 

•d  . 

I| 

sg 

*! 

P*" 

ss 

II 

jl 

000000 

.464 

46875 

000000 

00000 

.432 

•1UO  1  V 

.43?5 

00000 

0000 

.46 

.454 

.3938 

.400 

.40MB 

0000 

000 

.40964 

.425 

.3625 

.372 

.... 

'.375 

000 

00 

.3648 

.38 

.3310 

.343 

.34375 

00 

0 

.32486 

.34 

.3065 

.324 

.3125 

9 

1 

.2893 

.3 

.2830 

.300 

.*227 

.28125 

i 

2 

.25763 

.284 

.2625 

.276 

.219 

.265625 

2 

3 

.22942 

.259 

.2437 

.252 

.212 

.25 

3 

4 

.20431 

.238 

.2253 

.232 

.207 

.234376 

4 

5 

.18194 

.22 

.2070 

.212 

.204 

.21875 

5 

6 

16202 

.203 

.1920 

.192 

.201 

.20312$ 

6 

7 

.'14428 

.18 

.1770 

.176 

.199 

.1875 

7 

8 

12849 

.165 

.1620 

.160 

.197 

.171875 

8 

9 

'11443 

.148 

.1483 

.144 

.194 

.15625 

9 

10 

'10189 

.134 

.1350 

.128 

.191 

.140625 

10 

11 

"090742 

.12 

.1205 

.116 

.188 

.125 

11 

12 

080808 

.109 

.1055 

104 

.185 

.109375 

12 

13 

071961 

.095 

.0915 

.092 

482 

.09375 

13 

14 

064084 

.083 

.0800 

.080 

.180 

.078125 

14 

15 

.057068 

.072 

.0720 

.072 

.178 

.0708125 

15 

16 

05082 

.065 

.0625 

.064 

.175 

.0625 

16 

17 

.045257 

.058 

.0540 

.056 

.172 

.05625 

17 

18 

.040303 

.049 

.0475 

.048 

.168 

.05 

18 

19 

03589 

.042 

.0410 

.040 

.164 

.04375 

19 

20 

031961 

.035 

•0348 

.036 

.161 

.0375 

20 

21 

.'028462 

,032 

.03175 

.032 

.157 

.034375 

21 

22 

.025347 

.028 

.0286 

.028 

.155 

.03125 

22 

23 

022571 

.025 

.0258 

.024 

.153 

028125 

23 

24 

"0201 

.022 

.0230 

.022 

.151 

.025 

24 

25 

'0179 

.02 

.0204 

.020 

.148 

.021875 

25 

26 

'01594 

,018 

.0181 

.018 

.146 

.01875 

26 

27 

014195 

.016 

.0173 

.0164 

.143 

.0171876 

27 

28 

!012641 

.014 

.0162 

.0149 

.139 

.015625 

28 

29 

.011257 

.013 

.0150 

.0136 

.134 

.0140625 

29 

30 

010025 

.012 

.0140 

.0124 

.127 

.0125 

30 

31 

'008928 

.01 

.0132 

.0116 

.120 

.0109375 

31 

32 

"00795 

.009 

.0128 

.0108 

.115 

.01015625 

32 

33 

'00708 

.008 

.0118 

.0100 

.112 

.009375 

33 

34 

*006304 

.007 

.0104 

.0092 

.110 

.00859375 

34 

35 

'  005614 

.005 

.0095 

.0084 

.108 

.0078125 

35 

36 

005 

.004 

.0090 

.0076 

.106 

.00703125 

36 

87 

004453 

.... 

.0068 

.103 

.006640625 

37 

38 

'003965 

.... 

.... 

.0060 

.101 

.00625 

38 

39 

'.003531 

.0052 

.099 

39 

40 

.003144 

.0048 

.097 

40 

220 


HARDENING,    TEMPERING    AND    ANNEALING. 


U.  S.   STANDARD  SCREW  THREADS. 


Diameter 
of  Screw. 

Threads  to 
Inch. 

Diameter  at  Root 
of  Thread. 

Width  of 
Flat. 

# 

20 

.185 

.0063 

A 

18 

.2403 

.0069 

/8 

16 

.2936 

.0078 

A 

14 

.3447 

.0089 

Yz 

13 

.4001 

.0096 

A 

12 

.4542 

.0104 

# 

11 

.5069 

,0114 

X 

10 

.6201 

.0125 

# 

9 

.7307 

.0139 

i 

8 

.8376 

.0156 

SH 

7 

.9394 

.0179 

IK 

7 

1.0644 

.0179 

1/8 

6 

1  .  1585 

.0208 

ttf 

6 

1.2835 

.0208 

1# 

5^ 

1.3888 

.0227 

IK 

5 

1.4902 

.0250 

1% 

5 

1.6152 

.0250 

2 

4^ 

1.7113 

.0278 

W 

4/2 

1.9613 

.0278 

*x 

4 

2.1752 

0313 

2*4 

4 

2.4252 

.0313 

3 

3/2 

2.6288 

,;0357 

*K 

3J4 

2.8788 

.0357 

3^ 

3* 

3.1003 

.0385 

8* 

3 

3.3170 

.0417 

4 

3 

.3.5670 

.0417 

4* 

2tt 

3.7982 

.0435 

4^ 

W 

4.0276 

.0455 

4* 

*ti 

4.2551 

.0476 

5 

*y* 

4.4804 

.0500 

5* 

*Y2 

4.7304 

.0500 

5K 

2/8 

4.9530 

.0626 

5^ 

23/g 

5.2030 

.0526 

6 

2* 

5.4226 

.0556 

MISCELLANEOUS    METHODS,  TABLES,  ETC. 


221 


k-  p-  —  >j 

Formula  : 
ft  —  pitch  — 

.    .    .<     . 
'^SS^SS^S^S^^^^^^^^S 

Diameter    
No.  Threads  per  inch  . 

No.  threads  per  inch 
d  =  depth  -px.  8660. 

U      A      X      A      K      A      X      H      % 

20      18      16      14      12      12      11       11      10 

%$$!!%    IX    1%    !/^     1%    1% 

it 
10 

No.  Threads  per  inch  . 
Diameter 

998776655 
2        2^    2X  %%    2K    2%    2%    2%     3 

4K 

No.  Threads  per  inch. 

$X    3%    S1^  3%    3%    3%     4 

3^ 

No.  Threads  per  inch  . 

3K    3^    *X  3K    3        3        3 

UNITED  STATES  STANDARD  THREAD. 

-/•HJh— 

Formula  :                                 -^ 

Diameter    . 

No  threads  per  inch 
d^=  depth  =px  .6495. 

/=flat  =  ^ 

••      •          X         A         %         A         712         T9^6          /^         % 

No.  Threads  per  inch  . 
Diameter    .... 

.     .       20      18      16      14      13      12      11      10 

9 
2 

No.  Threads  per  inch  . 

..87        7        6        6        5^    5        5 

2 

No.  Threads  per  inch  . 
Diameter        . 

.     .       4J£  4^    4        4        4        4        3i,£    3^ 
.     .      3l£  3^    3^    3^    3%    3>s     4 

BK 

No.  Threads  per  inch  . 

..      3>^  3^    3^    3^    3        3        3 

WHITWORTH  STANDARD  THREAD. 

iJZv^k 

Formula  :                                 ^ 

No.  threads  per  inch 
d  =  depth  =  p  X  .64033. 
T  —  radius  —  p  X   1373 

Diameter 

X     35e     %     A     K     A     %     H     M 

it 

No.  Threads  per  inch  . 
Diameter        .... 

20      18      16      14      12      12      11      11      10 

10 

No.  Threads  per  inch. 

998776655 
2        2^    2X    23£    2^    2%    2%    2^g     3 

4^ 

No.  Threads  per  inch  . 
Diameter  .              .     . 

4^    4>^     4        4        4        4        3^    3^    8^ 

3M    33^    3><    3%    3%    3;g     4 

3K 

No.  Threads  per  inch  . 

Ol  /       O1/       Ol/        O1X       Q              Q              Q 
O^      "/4      "74       "74       u           O           O 

y^TTBlTT^, 
^             F  THE 

1  UNIVERSITY 

^^                  nr 

222 


HARDENING,    TEMPERING    AND    ANNEALING. 


THE   ACME    STANDARD   THREAD. 


The  Acme  Standard  Thread  is  an  adaptation  of  the  most 
commonly  used  style  of  Worm  Thread  and  is  intended 
to  take  the  place  of  the  square  thread. 

It  is  a  little  shallower  than  the  Worm  Thread,  but  the 
same  depth  as  the  square  thread  and  much  stronger  than 
the  latter. 

The  various  parts  of  the  Acme  Standard  Thread  are 
obtained  as  follows: 

Width  of  Point  of  tool  for  Screw  or  Tap  Thread 

.3707 
— .0052 

No.  of  Thds.  per  in. 

Width  of  Screw  or  Nut  Thread  =  — 


•3707 


No.  of  Thds.  per  in. 

Diameter  of  Tap  —  Diameter  of  Screw  +  .020. 
Diameter  of  Tap  or  Screw  at  Root  = 

Ii 
+  .020 


No.  of  Linear  Thds.  per  in. 

i 


Depth  of  thread  — 


2  x  No.  of  Thds.  per  in. 


.010 


TABLE    OF    THREAD    PARTS. 


No.  of 

Depth 

Width  at 

Width  at 

Space  at 

Thickness 

Threads 

of 

Top  of 

Bottom  of 

Top  of 

at  Root  of 

per  incb. 

Thread. 

Thread. 

Thread. 

Thread. 

Thread. 

1 

.5100 

.3707 

.3655 

.6293 

.6345 

1^ 

.3850 

.2780 

.2728 

.4720 

.4772 

a 

.2600 

.1853 

.1801 

.3147 

.3199 

3 

.1767 

.1235 

.1183 

.2098 

.2150 

4 

.1350 

.0927 

.0875 

.1573 

.1625 

5 

.1100 

.0741 

.0689 

.1259 

.1311 

6 

.0933 

.0618 

.0566 

.1049 

.1101 

7 

.0814 

.0529 

.0478 

.0899 

.0951 

8 

.0725 

.0463 

.0411 

.0787 

.0839 

9 

.0655 

.0413 

.0361 

.0699 

.0751 

10 

.0600 

.0371 

.0319 

.0629 

.0681 

MISCELLANEOUS    METHODS,  TABLES,  ETC. 


223 


AVERAGE   CUTTING    SPEED   FOR  DRILLS. 

The  following  table  represents  the  most  approved  prac- 
tice in  rate  of  cutting  speed  for  drills  ranging  from  1-16 
inch  to  3  inches  in  diameter. 


Diam.  of 
Drills 

Speed  on 
C.  Iron 

Speed  on 
Steel 

Diam.  of 
Drills 

Speed  on 
C.  Iron 

Speed  on 
Steel 

A 

2,289 

1,704 

1A 

71 

46 

X 

1,134 

840 

1% 

67 

43 

A 

749 

553 

in 

64 

41 

X 

556 

409 

*M 

61 

39 

T5* 

441 

322 

113 

58 

37 

% 

363 

263 

iX 

56 

35 

7 
16 

309 

224 

HI 

53 

33 

# 

267 

193 

2 

51 

31 

A 

235 

169 

2TV 

49 

29 

% 

210 

150 

2L/ 

47 

28 

B 

189 

134 

2T8<r 

45 

26 

X 

171 

121 

2k 

43 

25 

if 

156 

110 

2i5e 

41 

24 

78 

144 

100 

2% 

39 

23 

il 

133 

92 

2y7« 

38 

21 

1 

123 

85 

BK 

36 

20 

V* 

114 

79 

«A 

35 

19 

\y% 

107 

73 

2^ 

34 

18 

IA 

100 

68 

Hi 

32 

17 

*x 

94 

63 

2% 

31 

16 

1^ 

89 

59 

HI 

30 

15 

1% 

83 

56 

2% 

29 

15 

!iV 

79 

52 

HI 

28 

14 

ix 

75 

49 

3 

27 

13 

224 


HARDENING,    TEMPERING   AND   ANNEALING. 


TABLE  OF  CUTTING  SPEEDS. 


Feet$ 
Minute. 

5' 

10' 

15' 

20' 

25' 

30' 

35' 

40' 

45' 

so' 

Diam. 

REVOLUTIONS  PER  MINUTE. 

y 

38.2 

76.4 

114  6 

152.9 

191.1 

229.3 

267.5 

3°5-7 

344-0 

382.2 

% 

30.6 

61.2 

91.8 

122.5 

I53-I 

183-7 

214.3 

244,9 

275-5 

306.1 

4^« 

25-4 

50.8 

76.3 

101.7 

127.! 

'52.5 

178.0 

203.4 

228.8 

254.2 

/o 

21.8 

43-6 

65-5 

87.3 

109.1 

130.9 

i52-7 

^74-5 

196.3 

2*8.9 

19.1 

38.2 

57-3 

76.4 

95-5' 

114.6 

133-8 

152.9 

172.0 

191.1 

V^ 

17.0 

34-o 

51.0 

68.0 

85.0" 

IO2.O 

119.0 

136.0 

153.0 

170.0 

$4 

30.6 

45.8 

61.2 

76-3 

9i.B 

106.9 

122.5 

137-4 

I53-1 

13.9 

27.8 

41.7 

55-6 

69.5 

83-3 

97-2 

in.  i 

125.0 

138.9 

y 

12.7 

25-4 

38.2 

50.8 

76-3 

89.2 

101.7 

114.6 

127.1 

% 

ii.  8 

23-5 

3S-o 

47-o 

58.8 

70-5 

82.2 

93-9 

105.7 

117.4 

£4 

10.9 

21.8 

32-7 

43-6 

54-5 

65-5 

76.4 

873 

98.2 

TOQ.  I 

/k 

10.2 

20.4 

40.7 

50-9 

61.  i 

71-3 

81.5 

91.9 

IOI.^F 

2 

9-6 

19.1 

28.7 

38.2 

47.8 

57-3 

66.9 

76.4 

86.0 

45-5 

2\4 

8-5 

17,0 

25-4 

34-o 

42.4 

51.0 

59-4 

68.0 

76.2 

85.0 

2% 

•7-6 

»5-3 

22.9 

30.6 

38-2 

45-8 

53-5 

61.2 

68.8 

76.3 

2% 

6.9 

13  9 

20.8 

27.8 

34-7 

41.7 

48.6 

55-6 

62.5 

69.5 

31 

6.4 

12.7 

IQ.I 

25-5 

31-8 

38-2 

44-6 

51.0 

57-3 

63.7 

5-5 

10.9 

I6.4 

21.8 

27-1 

32-7 

38-2 

43-6 

49.1 

54-5 

4 

4.8 

9.6 

J4-3 

19.1 

23-9 

28.7 

33-4 

382 

43-0 

47-8 

4//2 

4.2 

8-5 

12.7 

16.9 

21.2 

.25-4 

29.6 

34.0 

38  i 

42.4 

5 

3-8 

7-6 

"•5 

15-3 

I9.I 

'22.9 

26.7 

30-6. 

34-4 

38.2 

f 

3-5 
3-2 

6.4 

10.4 
9.6 

13-9 
12.7 

17.4 

15-9 

20.8 

19.1 

24-3 
22.3 

2^.8 

25'  5 

3^-3 
28.7 

34-7 
31-8 

7 

2-7 

5-5 

8.1 

10.9 

13-6 

16.4 

tq.  i 

21.8 

24.6 

27-3 

8 

2.4 

4.8 

7-2 

9.6 

II.9 

14.3 

16.7 

19  I 

21.  1 

23-9 

9 

2.1 

4.2 

6.4 

8-5 

10.6 

12.7 

14.9 

17.0 

I9.I 

21.2 

10 

•9 

3-8 

5-7 

7-6 

9.6 

n-5 

13-4 

J5  3 

17.2 

ig.I 

ii 

•7 

3-5 

5-2 

6.9 

8.7 

10.4 

12.2 

J3-9 

15-6 

17.4 

12 

.6 

3-2 

4.8 

6.4 

8.0 

9-6 

II.  I 

12.7 

14-3 

15-9 

J3 

•5 

2.9 

4-4 

S«9 

7-3 

8.8 

10.3 

ii.  8 

13.2 

14.7 

>4 

-4 

2.7 

4.1 

5-5 

6.8 

8.1 

9.6 

10.9 

I2.3 

13.6 

15 

•3 

2.5 

3-8 

5.1 

6.4 

7-6 

8.9 

IO.2 

"-5 

12-7 

16 

.2 

2.4 

3-6 

4.8 

6.0 

7.2 

8.4 

9.6 

10.7 

11,9 

17 

.1 

2.2 

3-4 

4-5 

5-6 

6-7 

7-9 

0.0 

10.  I 

II.  2 

18 

,J 

2.1 

S-2 

4.2 

5-3 

6.4 

7-4 

i-5 

9.6 

10.6 

19 

.O 

2.0 

4.0 

5.0 

6.0 

7.0 

8.0 

9.1 

10.  1 

20 

.O 

•9 

2.9 

3-8 

4-8 

5-7 

6.7 

7.6 

8.6 

9.6 

21 

•9 

.8 

2-7 

3.-6 

4-5 

5-5 

(5.4 

7-3 

8.1 

9-1. 

22 

•9 

•7 

2.6 

3-5 

4-3 

5-2 

6.1 

6.9 

7-8 

8-7 

23 

.8 

•7 

2-5 

3-3 

4.1 

5«o 

5-8 

6.6 

7-5 

8-3 

24 

.8 

.6 

2.4 

3-2 

4.0 

4.8 

5-6 

6.4 

7-2 

8.0 

25 

.8 

•5 

2-3 

3  i 

3-8 

4.6 

5-3 

6.1 

6.9 

7.6 

26 

•7 

•5 

2.2 

2.9 

3-7 

4-4 

5-9 

6.6 

7-3 

27 

•7 

•4 

2.1 

2.8 

3-5 

4.2 

5-0 

5-7 

6.4 

28 

•7 

«4 

^2.0 

2.7 

3-4 

4.1 

4.8 

5-5 

6.1 

6.  8 

29 

•7 

•3 

2.0 

2.6 

3-3 

4.0 

4.6 

5-3 

5-9 

6.6 

30 

.6 

•3 

1.9 

2-5 

S-2 

3-8 

4-5 

5-7 

6.4 

MISCELLANEOUS    METHODS,  TABLES,  ETC.  225 


The  preceding  table  is  a  convenient  one  for  rinding  the 
number  of  revolutions  per  minute  required  to  give  a  peri- 
phery speed  from  5  to  50  feet  per  minute  of  diameters 
from  y2  inch  to  30  inches. 

EXAMPLES — A  mill  2  inches  diam.  to  have  a  periphery 
speed  of  35  feet  per  minute,  should  make  about  67  revo- 
lutions, while  a  i^-inch  mill  should  make  120  revolu- 
tions to  have  the  same  periphery  speed.  If  a  34-inch 
mill  makes  250  revolutions  per  minute,  the  periphery  speed 
is  about  50  feet. 

Horse  Power  of  Belts. — A  good  method  of  finding  the 
power  of  a  belt,  assuming  800  feet  travel  per  minute  of 
i  inch  single  belt  per  horse  power. 

FORMULA — .00033  D.  R.  B  =  Horse  power. 

D  =  Diameter  of  pulley  in  inches. 
R  =  Revolutions  of  pulley  per  minute. 
B  — Width  of  belt  in  inches. 

EXAMPLE — i8-inch  pulley,  3-inch  belt,  150  revolutions 
per  minute,  .00033  x  18  x  150  x  3  —  2.67  H.  P. 

If  looo  feet  is  assumed  instead  of  800  feet,  use  constant 
.00026  in  place  of  .00033. 


CUTTER   LUBRICANT. 

A  good  lubricant  for  cutters  milling  steel  or  wrought 
iron,  is  i  Ib.  tallow  or  i  Ib.  hard  or  soft  soap.  Boil  and 
add  water  until  about  the  consistency  of  cream. 


CHAPTER  XII. 

GRINDING THE    ACCURATE    AND    RAPID    GRINDING    OF    TOOLS    AND 

SMALL    MACHINE    PARTS EMERY    WHEELS. 

Cutter  and  Tool  Grinding. 

A  subject  germain  to  the  treatment  of  steel  is  that  of  grinding, 
as  in  most  lines  of  steel  working  it  occupies  an  important  posi- 
tion. In  the  following  are  shown  illustrations  of  approved  ma- 
chines for  the  grinding  of  fine  tool  work  and  accurate  small  ma- 
chine parts.  Descriptions  are  also  given  of  the  correct  methods 
of  grinding  the  different  tools  and  parts. 

The  machine  illustrated  in  Fig.  146  is  of  a  type  used  ex- 
tensively for  general  toolroom  work  and  is  one  of  a  class  of  uni- 
versal cutter  and  tool  grinders  which  has  been  greatly  improved 
and  developed  during  the  last  few  years.  It  may  be  used  to  grind 
accurately  and  rapidly  work  of  the  following  kinds  and  sizes : 

Milling  machine  cutters  12  inches  in  diameter  when  not  more 
than  i  inch  wide. 

Work  14  inches  long  held  between  centers  when  the  diameter 
of  rotation  is  not  more  than  8  inches.  These  dimensions  are  given 
as  the  limit  for  irregular  pieces  and  not  for  heavy,  solid  cylin- 
ders. 

Work  14  inches  long  can  be  ground  by  using  an  emery  wheel 
on  each  side  of  the  head. 

Reamers  and  shell  counterbores  of  large  or  small  sizes. 

Gear  cutters  and  formed  cutters  of  every  description. 

Flat  surfaces,  such  as  shear  plates,  dies  and  gages. 

Hardened  bushing  and  other  pieces  to  be  ground  internally. 

Conical  surfaces,  such  as  taper  bearings  and  mandrels,  and 
small  cylindrical  machine  parts  which  are  to  be  finished  with  ex- 
treme accuracy. 

The  foregoing  list  does  not  give  the  limit  of  the  capacity  of 
machine,  but  rather  indicates  in  a  general  way  what  is  possible  in 
its  use. 

For  a  more  particular  presentation  of  the  kinds  of  work  which 
can  be  and  are  actually  ground  on  such  machines,  reference  is 
made  to  the  following  pages. 


GRINDING. 


227 


Prominent  Features. 

Those  familiar  with  grinding  the  side  teeth  of  side  milling  and 
angular  cutters  are  aware  that  the  tooth  rest  must  be  set  to  the 
exact  height  so  as  to  bring  the  cutting  edge  of  the  tooth  to  be 
ground  in  an  exact  parallel  line  with  the  slide.  In  some  machines 


FIG.    146. — CINCINNATI  UNIVERSAL  CUTTER   AND  TOOL  GRINDER. 

this  adjustment  of  the  tooth  rest  for  this  grinding  is  complicated. 
The  difficulty,  however,  is  overcome  in  this  machine,  as  no  atten- 
tion is  required  to  adjust  the  tooth  rest,  since  it  is  centrally  fixed 
for  all  diameters  of  cutters.  The  tooth  rest  travels  with  the  cut- 
ter, except  in  the  grinding  of  spiral  mills  and  large  saws. 


228 


HARDENING,    TEMPERING   AND   ANNEALING. 

4  ------      3'     --- 


N — 
Sr 
jL-im 


_  «-  —  ^ 


a 


i 


FIG.   147. — SHAPES   AND  SIZES  OF  EMERY  WHEELS   TO   USE   FOR   TOOL 

GRINDING. 


GRINDING. 


229 


FIG.  148. — SAMPLES  OF  GROUND  WORK  DONE)  IN  UNIVERSAL  CUTTER. 
AND   TOOL   GRINDER,    FIG.    146. 


230 


HARDENING.,    TEMPERING    AND    ANNEALING. 


The  side  teeth  of  angular  and  side  milling  cutters  are  ground 
off  with  practically  a  straight  line  clearance.  This  is  done  with  a 
cup-shape  emery  wheel  3  inches  in  diameter  on  the  left  side  of 
the  machine.  The  advantages  of  grinding  side  teeth  with  a  fair 
size  emery  wheel,  and  at  the  same  time  grinding  a  straight  line 
clearance  with  an  accompanying  strong  cutting  edge,  are  known 
to  those  who  have  heretofore  been  compelled  to  use  a  small  wheel 
grinding  a  hollow  clearance  and  weak-cutting  edge.  (See  Fig. 
149-) 

To  prevent  the  drawing  of  the  temper  from  cutting  edges  of 
side  mills  and  the  side  teeth  of  angular  cutters,  etc.,  which  have  a 


FIG.   149. — GRINDING   SIDE   TEETH. 

broad  surface,  it  is  important  that  the  heel  of  the  tooth  be  stocked 
out  first  at  a  sharp  angle,  and  only  a  small  portion  left  to  be 
ground  at  a  different  angle.  The  change  from  stocking  out  to 
the  grinding  of  the  cutting  edge  is  quickly  made  by  moving  the 
knee  a  few  degrees  around  the  column. 

This  feature  of  revolving  the  knee  around  the  column  has  also 
the  following  advantages: 

Work  can  be  brought  in  contact  with  the  emery  wheels  on 
either  side  of  the  wheel  without  rechucking.  Also  the  article  to 
be  ground  can  be  brought  in  contact  with  the  emery  wheel  in  the 
most  favorable  position  to  either  wheel  for  rapid  grinding.  For 
an  example,  a  side  milling  cutter  may  have  the  outer  teeth  ground 
off  on  the  straight  face  emery  wheel  on  the  right  side  of  the  ma- 


GRINDING. 


231 


chine,  and  the  side  teeth  on  the  cup-shape  wheel  at  the  left  side 
of  the  machine,  without  taking  the  cutter  off  the  arbor  or  disturb- 
ing the  tooth  guide. 

Cutters  of  small  diameters  and  sharp  angles  can  be  ground 
without  the  cutter,  mandrel  or  centers  striking  the  belt  or  emery 
wheel  head.  Also  in  grinding  the  shoulders,  on  work  revolved 
between  centers,  the  periphery  instead  of  the  side  of  a  flat  wheel 
can  be  used. 

Grinding  a  Spiral  Mill. 

Fig.  150  shows  the  long  slide  at  the  rear  of  the  column  and 
nearly  parallel  to  the  emery  wheel  spindle,  the  two  swivels  set  at 


FIG.   150. — GRINDING   A  SPIRAL  MILL. 

zero,  a  flat  wheel  on  the  right  of  the  emery  wheel  head  and  the 
mill  on  the  mandrel  held  between  centers. 

Fig.  151  shows  a  side  elevation  of  the  wheel,  the  centering 
gage,  the  tooth  rest  No.  2  and  the  end  of  the  mill. 

Fig.  152  is  an  elevation  showing  the  rim  of  the  wheel,  the 
face  of  the  mill  and  the  tooth  rest  in  the  position  required  when 
the  mill  is  turned  for  grinding  the  next  tooth. 

Directions :  Adjust  the  plane  of  centers  below  the  plane  of 
the  spindle  the  distance  required  for  clearance.  If  the  mill  is 
cylindrical,  set  the  table  at  zero ;  and  if  not,  set  it  for  the  required 
taper.  Set  the  stops  on  the  long  slide  so  that,  the  mill  having 
passed,  the  cutter  will  still  be  held  by  the  flexible  part  of  the 
tooth  rest,  which  will  then  act  as  a  spring  pawl  when  turning  the 
mill  to  bring  the  next  tooth  into  position  for  grinding.  In  setting 


232 


HARDENING,    TEMPERING   AND   ANNEALING. 


the  tooth  rest  the  centering  gage  must  come  directly  opposite  to 
part  of  the  wheel  which  strikes  the  cutter. 

Grinding   Angular   Cutters. 
Fig.  153  illustrates  the  grinding  when  the  cutter  is  left-hand. 


The  flat  wheel  is  on  the  right-hand  end  of  spindle,  the  long 
slide  is  at  the  rear  and  right-hand,  the  cutter  is  held  on  work 
spindle  and  the  tooth  rest  No.  4  is  on  the  horizontal  swivel. 

Directions :     Set  the  plane  of  centers  below  plane  of  spindle. 


GRINDING.  233. 

the  distance  required  for  clearance.  Set  the  long  slide  at  a  con- 
venient angle,  and  then  adjust  the  horizontal  swivel  to  the  angle 
required  for  the  cutter. 

Fig.  154  illustrates  the  grinding  when  the  cutter  is  right-hand. 


FIG.   153. — GRINDING  A   LEFT-HAND   ANGULAR   CUTTER. 


FIG.    154. — GRINDING   A   RIGHT-HAND   ANGULAR   CUTTER. 

The  explanations  and  directions  for  Fig.  153  are  sufficient  for 

Fig-  154. 

Grinding  Side  Milling  Cutters. 

Fig-  155  shows  the  situation  of  the  long  slide  at  the  back  of 
the  column,  the  cutter  held  by  work  spindle  alone,  the  flat  wheel 
on  the  right  of  the  emery  wheel  head,  and  the  tooth  rest  No.  3 
fastened  to  the  horizontal  swivel. 


234 


HARDENING,    TEMPERING   AND   ANNEALING. 


Directions:  Set  the  plane  of  centers  the  distance  below  the 
plane  of  the  spindle  required  for  clearance. 

Fig.  156  shows  the  left-hand  radial  teeth  in  position  for  grind- 
ing, the  3-inch  cup  wheel  on  the  left  of  the  emery  wheel  head, 


the  long  slide  on  the  left,  the  universal  head  on  the  end  of  the 
table  and  tooth  rest  No.  3  on  the  horizontal  swivel. 

It  will  be  observed  in  the  cuts  that  the  side  of  the  cutter 
opposite  the  one  being  ground  is  always  closer  to  the  emery  whee] 
head  than  the  other ;  that  is,  the  index  on  the  knee  will  point  about 
5  degrees  beyond  the  90  degree  point. 


GRINDING. 


235 


Directions :  Set  the  vertical  swivel  so  as  to  depress  the  outer 
end  of  the  work  spindle  the  number  of  degrees  required  for  clear- 
ance. This  ranges  from  5  degrees  to  20  degrees,  depending  upon 
the  clearance  required. 

The  manner  in  which  shell  counterbores  may  be  ground  is 


shown  clearly  in  Fig.  157,  and  but  little  description  is  necessary. 
In  grinding  such  tools,  a  stud,  which  fits  the  taper  hole  in  the 
work  spindle  and  the  hole  in  the  counterbore,  is  required. 


236 


HARDENING,    TEMPERING    AND    ANNEALING. 


Grinding  Milling  Cutters  or  Metal  Slitting  Saws  from  8  to  12 

Inches  in  Diameter. 

Fig.  159  is  a  plan  showing  the  3-inch  emery  wheel,  the  saw  or 
cutter,  the  horizontal  swivel  and  the  tooth  rest  No.  3  in  position 


FIG.   157.— GRINDING  SHELL   COUNTERBORES. 


3'DlAMETER 


PIG.   158.  FIG.  159. 

GRINDING   MILLING   CUTTERS   OR   METAL  SAWS   OF   LARGE   DIAMETERS. 


GRINDING. 


237 


for  grinding,  while  Fig.  158  shows  an  elevation  of  Fig.  159,  show- 
ing the  long  slide  at  the  rear  of  the  column  end  parallel  to  the  em- 
ery wheel  spindle,  the  universal  head  at  the  tail  stock  end  of  the 
table,  the  saw  held  by  work  spindle  alone,  and  the  3-inch  emery 
wheel  on  the  left  of  the  wheel  head.  The  saw  is  clamped  to  the 
work  spindle  by  means  of  the  long  screw  with  nut  and  collar  for 
that  purpose. 


238  HARDENING,    TEMPERING    AND   ANNEALING. 

Directions :  Set  the  plane  of  the  centers  below  the  spindle 
plane  the  distance  required  for  clearance.  Set  both  swivels  and 
table  at  zero. 

Large  saws,  up  to  24  inches  in  diameter,  such  as  are  used  in 
cold  saw  cutting-off  machines,  are  ground  as  shown  in  Fig.  160. 
It  will  be  noticed  that  the  universal  head  is  here  reversed  on  the 
table  and  the  tooth  rest  placed  on  the  emery  wheel  head. 

Gear  Cutter  Grinding. 

Figs.  161  and  162  represent  an  elevation  and  plan  of  the  gear- 
cutter  grinding  attachment.  The  platen  which  holds  cutter  is 
fitted  to  the  slot  in  the  table  and  clamped  to  it  by  bolt  and  nut. 


FIG.   l6l. — ELEVATION    OF   GEAR   CUTTER   GRINDING   ATTACHMENT. 

The  table  should  be  set  right  angular  to  the  slide  and  the  slide 
at  a  right  angle  to  the  axis  of  the  emery  wheel  spindle  (see  dotted 
lines),  as  this  position  brings  only  the  edge  of  the  emery  wheel  in 
contact  with  the  work,  permitting  a  heavy  cut  to  be  taken  without 
danger  of  heating. 

In  adjusting  the  cutter  for  grinding,  the  centering  gage  be- 
longing to  the  attachment  is  set  over  against  the  face  of  the  tooth. 
Then  the  pawl  holder  is  clamped  so  as  to  bring  the  pawl  tooth  rest 
against  the  heel  of  the  tooth.  After  swinging  the  centering  gage 
out  of  the  way,  as  shown  in  cut,  the  grinding  may  proceed.  Thus, 
with  this  arrangement,  gear  and  formed  cutters  can  be  ground 
correctly  and  in  less  time  than  by  hand.  Bushings  for  the  various 
sizes  of  holes  in  standard  gear  cutters  and  emery  wheel  No.  3 
^re  required  with  this  attachment. 


GRINDING. 


239 


240 


HARDENING,    TEMPERING    AND   ANNEALING. 


Grinding  Formed  Cutters. 

Fig.  163  shows  the  table  and  long  slide  on  the  right  of  the  col- 
umn, the  dish-shaped  wheel  on  the  right-hand  end  of  the  spindle, 
the  two  arms  by  means  of  which  the  center  of  the  cutter  may 
be  held  below  the  top  of  the  table  and  the  tooth  rest  No.  5  which 
engages  with  the  heel  of  the  tooth  to  be  ground. 

Directions :  Set  the  axis  of  the  long  slide  at  right  angle  to 
that  of  the  spindle  by  means  of  dial  on  column.  Set  the  lower  line 


FIG.    163. — GRINDING   A   FORMED   CUTTER. 

of  centers  so  that  it  will  intersect  the  vertical  diameter  at  the 
side  of  the  wheel.  This  adjustment  can  be  readily  made  by  bring- 
ing the  point  of  the  tail  stock  center  nearly  in  line  with  the  side  of 
a  straight  edge  held  vertically  against  the  flat  side  of  the  wheel. 
Put  the  cutter  on  a  mandrel  between  centers  and  set  the  face  of  a 
tooth  against  the  side  of  the  wheel,  making  an  allowance  for 
amount  to  be  ground  off.  To  hold  the  face  in  this  position,  ad- 
just tooth  rest  No.  5  to  the  heel  of  the  tooth.  Determine  the 
depth  of  cut  by  short  slide. 


GRINDING. 


24I 


How  to  Grind  a  Worm  Wheel  Hob. 

Fig.  164  shows  the  long  slide  on  the  left  of  the  column,  the 
special  attachment  on  the  table  for  holding  the  mandrel,  the  disk- 
shape  wheel  No.  3  on  the  left-hand  end  of  the  spindle  and  the 
table  in  line  with  the  long  slide. 

Directions:      See   those   given    for   grinding   formed   cutters. 

Grinding  a  Hand  Reamer. 
Fig.  165  shows  the  long  slide  on  the  left,  the  cup-shape  wheel 


FIG.   164. — GRINDING  A  WORM   WHEEL  HOB. 

on  the  left-hand  end  of  spindle  and  the  tooth  rest  No.  I  fastened 
to  the  top  of  the  table. 

Directions :  Set  the  tooth  rest  below  plane  of  centers  a  suffi- 
cient distance  for  clearance  when  grinding  straight  reamers.  Set 
the  table  to  grind  straight.  To  grind  bevel  on  end  of  reamer  set 
table  to  angle  required,  or  as  shown  in  Fig.  166. 

Grinding  a  Taper  Reamer. 

Fig.  167  shows  the  long  slide  at  the  rear  right  of  emery  wheel 
head,  the  table  set  obliquely  to  the  side,  the  swivels  at  zero,  the 
reamer  between  dead  centers,  a  flat  wheel  at  the  right-hand  end 
>of  the  spindle  and  the  tooth  rest  No.  3  fastened  to  the  swivel. 

Directions:     Set  the  tooth  rest  in  the  plane  of  centers.     Set 


242  HARDENING,    TEMPERING   AND   ANNEALING. 


.  165. — GRINDING  A  HAND  REAMER. 


FIG.  l66. — GRINDING  BEVEL  ON  END  OF  REAMER. 


GRINDING. 


-'43 


the  plane  of  centers  below  the  plane  of  spindle  the  distance  re- 
quired for  clearance.  Set  the  table  at  the  angle  required  for 
taper. 

How  to  Grind  a  Hardened  Drilling  Jig  Bushing. 
Fig.  1 68  shows  the  emery  wheel  spindle  with  flat  wheel  on  the 
right,  the  long  slide  on  the  right  to  the  rear  of  the  machine,  the 
table  set  at  zero,  the  grooved  pulley  running  loose  on  the  work 
spindle,  which  is  locked  by  a  knurled  screw,  the  jig  bushing  on  a 
mandrel  held  between  dead  centers  and  turned  by  a  dog  engaging 
with  the  grooved  pulley. 


FIG.   167. — GRINDING  A  TAPER   REAMER. 


Jdne  on*otio 


.    168. — GRINDING   A    HARDENED   JIG    BUSHING. 


244 


HARDENING,    TEMPERING   AND   ANNEALING. 


How  to  Grind  a  Taper  Spindle. 

Fig.  169  shows  the  long  slide  at  the  back  of  the  column,  the 
wheel  on  the  right  of  the  spindle,  the  table  set  for  the  required 
taper,  and  the  grooved  pulley  running  loose  on  the  work  spindle. 
In  circular  grinding  when  the  piece  is  held  by  the  work  spindle 
alone  the  grooved  pulley  is  locked  to  the  spindle. 


Emery  wheel  shape  No.  3  is  used  for  taking  deep  cuts ;  shape 
No.  5  for  finishing  the  surface. 

The  centers  in  work  that  has  to  be  ground  must  be  very  care- 
fully made  and  held  to  proper  shape.  Hardened  pieces  must  have 
centers  lapped  as  nearly  round  as  possible  in  order  to  obtain  good 
results.- 


GRINDING. 


245 


How  to  Grind  a  Slitting  Knife  with  Beveled  Edges. 
Fig.   170  shows  the  wheel  on  the  right  of  the  emery  wheel 
head,  the  long  slide  and  table  at  the  back  of  the  column,  the  hori- 
zontal swivel  set  at  the  angle  required  by  the  face  of  the  knife, 


the  grooved  pulley  locked  to  the  work  spindle  which  holds  the 
knife  by  bushing  and  long  screw. 

Internal  Grinding. 

Fig.  171  shows  the  long  slide  and  table  at  the  rear  of  the 
column  and  parallel  to  the  spindle  of  the  emery  wheel ;  the  piece 
to  be  ground  is  fastened  to  the  work  spindle,  the  internal,  grinding 


246  HARDENING,    TEMPERING    AND    ANNEALING. 


FIG.   IJI. — INTERNAL  GRINDING. 


FIG.  172.— GRINDING  A  STRAIGHT  EDGE. 


GRINDING. 


247 


attachment  is  fastened  to  the  emery  wheel  head,  with  its  pulley 
belted  to  the  pulley  on  the  right  of  the  column. 

Grinding  a  Straight  Edge. 
Fig.  172  shows  the  long  slide  on  the  left  and  parallel  to  the 


table,  the  straight  edge  clamped  to  its  place,  and  a  cup-shape 
wheel  on  the  left  of  the  spindle. 

Grinding  a  Shear  Plate. 

Fig.  173  is  an  elevation  showing  on  the  left  parallel  to  the 
table,  the  cup-shape  wheel  on  the  left  and  the  shear  plate  clamped 
to  the  table. 


248 


HARDENING,,    TEMPERING    AND   ANNEALING. 


How  to  Grind  u  Die  Blank  to  the  Required  Angle. 

Fig.  174  shows  the  long  slide  on  the  left,  the  table  across  the 
slide,  the  vise  in  the  place    of  the  universal  head,  the  cup-shape 


wheel  on  the  left,  and  the  vise  turned  on  its  pivot  to  the  required 
angle. 

Grinding  a  Formed  Tool  on  Its  Face. 

Fig.  175  shows  the  long  slide  on  the  left,  the  table  set  at  zero, 
the  cup-shape  wheel  on  the  left  of  the  emery  wheel  head,  the 
vise  set  at  90  deg.  for  convenience  in  holding  a  screw  machine 
form  tool  when  grinding  its  face. 


GRINDING. 


249 


FIG.  175. — GRINDING  THE   FACE   OF   A   FORMED  TOOI,. 


PIG.   176. — CUTTING  OFF  WITH  THE  EMERY  WHEEL. 


250 


HARDENING,    TEMPERING    AND    ANNEALING. 


The  Emery  Wheel  Used  as  a  Metal  Saw. 
The  engraving,  Fig.  176,  shows  the  vise  on  the  table  in  the 
place  of  the  universal  head,  the  long  slide  at  the  right  of  the  col- 
umn, the  table  across  the  slide,  and  a  wheel  on  the  right  of  the 
spindle  1-16  inch  thick  and  8  inches  in  diameter.  Brass  iubing 
and  small  steel  bars  can  be  readily  and  smoothly  cut  into  pieces 
by  means  described. 

Grinding  a  Gage  to  a  Given  Dimension, 
Fig.   177  is  a  plan  view  showing  the  long  slide  on  the  left, 


GRINDING. 


251 


the  table  across  the  slide,  the  vise  in  place  of  the  universal  head, 
the  gage  with  one  of  its  faces  against  the  cup-shaped  emery 
wheel  on  the  left. 

Attachment  for  Surface  Grinding. 

The  attachment  shown  in  Fig.   178  includes  the  vise  shown, 
with  angle  and  emery  wheel  No.  4. 


FIG.   178. — SURFACE  GRINDING  ATTACHMENT. 


The  vise  may  be  clamped  to  the  table  at  any  point  in  its 
length. 

Work  held  in  its  jaws  can  be  presented  at  any  angle  whatever 
in  regard  to  the  axis  of  the  emery  wheel  head,  by  making  suitable 
adjustment  of  the  swivel  vise,  the  table  and  the  long  slide. 

It  has  a  graduated  arc  to  measure  the  angle  of  elevation  or 
depression  at  which  the  work  is  presented  to  the  side  of  the 
emery  wheel. 


252 


HARDENING,    TEMPERING   AND   ANNEALING. 


Hoiv  to  Grind  Milling  Cutters  and  Metal-Slitting  Saute  Straight 

or  Concave. 

Fig".   179  shows  the  emery  wheel  head  with  a  wheel  on  the 
right,  the  long  slide  and  table  parallel  to  the  emery  wheel  spindle, 


the  horizontal  swivel  set  at  90,  and  the  saw  fastened  to  work- 
spindle. 

The  round  belt  should  be  as  loose  as  possible. 

General  Directions. 

Hold  the  cutter  to  the  tooth  rest  by  hand. 
In  all  cases  when  it  is  possible,  limit  the  movement  of  the 


GRINDING.  253 

long  slide  by  the  stops  furnished  for  the  purpose,  for  the  follow- 
ing reasons : 

It  prevents  the  wheel  from  striking  the  head  stock  or  cutter 
in  concave  grinding. 

It  prevents  the  wheel  from  running  too  deep  into  formed 
cutters  and  side  milling  cutters  when  grinding  radial  teeth. 

It  prevents  the  cutter  from  passing  off  the  tooth  rest,  besides 
being  convenient  in  quite  a  number  of  other  instances  occurring 
in  the  use  of  the  grinder. 

It  is  convenient  and  sometimes  necessary  in  grinding  cutters 
for  clearance  on  the  right-hand  end  of  the  emery  wheel  spindle, 
to  swing  the  knee  on  the  column  to  the  right  at  an  angle  of  from 
5  to  15.  This  applies  especially  in  angle  cutters  and  small 
cylindrical  cutters,  when  the  belt  is  liable  to  strike  the  cutter  or 
center. 

After  cutters  have  been  reground  once  or  twice  the  land  be- 
comes thick ;  it  is  very  convenient  under  these  conditions  to 
swing  the  knee  slightly  around  the  column  2  or  3  degrees,  and 
grind  with  a  heavy  broad  cut  between  the  teeth  so  as  to  reduce 
the  amount  of  the  land. 

After  the  land  is  reduced  to  the  proper  width  a  slight  move- 
ment of  the  knee  back  about  i  degree  will  alter  the  angle  of  the 
cut  in  such  a  way  as  to  produce  a  narrow  land  with  a  keen  cutting 
edge  without  danger  of  drawing  temper. 

The  life  of  a  cutter  by  this  means  is  very  much  prolonged. 

In  using  the  lever  or  screw  feed  handles,  adjust  them  by 
means  of  the  clamp  screws  at  bottom  of  long  slide  holder  to  the 
most  convenient  position. 

Use  the  centering  gage  for  determining  the  relative  height 
of  center  of  emery  wheel  spindle  and  tail  stock  center. 

Diamond  Tool  Holder. 

In  order  to  obtain  a  good  cutting  edge  and  make  a  smooth 
finish  on  work,  the  emery  wheel  on  a  universal  cutter  and  tool 
grinder  must  run  true  and  have  its  cutting  surface  parallel  with 
the  movement  on  the  slide  of  the  machine.  The  cut,  Fig.  180, 
shows  a  diamond  tool  and  holder  for  truing  emery  wheels.  This 
tool  is  made  to  be  used  either  by  hand  or  clamped  to  the  table 
of  fhe  machine  so  that  the  diamond  can  be  passed  across  the  wheel 
in  line  with  the  slide  in  any  position.  It  is  absolutely  necessary 
to  have  the  wheel  perfectly  true  on  work  ground  between  centers. 


254  HARDENING.,    TEMPERING    AND    ANNEALING. 

The  proper  use  of  this  device  will  greatly  increase  the  effi- 
ciency of  any  universal  cutter  and  tool  grinder,  both  as  to  quan- 
tity and  quality  of  work  produced. 

A  Small  Cutter  Grinder. 
The  small  "Garvin"  cutter  grinder  shown  in  Figs.  181  to  183 


FIG.   1 80. — DIAMOND  TOOL  HOLDER  FOR  WHEEL  TRUING. 

has  ample  capacity  for  all  the  ordinary  sizes  and  varieties  of  mill- 
ing cutters,  while  its  compactness  and  small  cost  render  it 
practicable  to  have  several  distributed  around  in  the  vicinity  of 


FIG.   l8l. — GRINDING   A   HOLLOW   MILL. 

each  group  of  milling  machines,  where  they  will  prove  a  valuable 
addition  to  the  plant  and  soon  pay  for  themselves  in  time  saved. 

The  machine  is  well  made  throughout,  and  will  grind  straight 
or  spiral  mills  and  shell  reamers  from  five  inches  diameter  and 
four  inches  face  down  to  the  smallest  side  or  face  mills ;  bevel  or 
angle-cutters  from  eight  inches  down ;  hand,  machine,  rose  and 


GRINDING.  255 

taper  reamers,  as  large  as  one  and  one-half  inches  diameter  and 
eight  inches  long ;  butt  mills,  either  straight  or  taper ;  cutters  for 
milling  T-slots,  and  hollow  mills,  such  as  used  on  screw-ma- 
chines ;  saws,  cutters  for  gear  teeth,  drills,  and  all  such  tools  as 
are  generally  ground  by  hand  can  also  be  handled.  Both  spindle 
and  arbor  are  of  steel,  hardened  and  ground,  the  latter  to  one 


FIG.  l82. — GRINDING  A  HAND  REAMER. 

inch  standard  size.  All  adjusting  screws  and  nuts  are  case- 
hardened  and  fit  wrench  attached  to  the  machine.  The  machine 
can  be  placed  on  the  bench  where  most  convenient  and  driven 
by  straight  or  quarter-turned  belt. 

The    spindle    is   provided    with    an    eccentric   adjustment    for 
feeding  the  wheel  against  the  work. 


PIG.    1 83. --GRINDING   AN   ANGULAR    CUTTER. 


HARDENING,    TEMPERING    AND   ANNEALING. 


FIG.   184. — ATTACHMENTS  FOR   "  GARVIN  "  UNIVERSAL,  CUTTER 
AND  TOOI,  GRINDER. 


i.  Reamer  Centers,  holding  work  three  inches  in  diameter,  and  at  any  length  up  to 
eighteen  inches.  Fig.  2.  Three-quarter  inch  Cutter  Arbor.  Fig.  3.  Three-quarter 
inch  Adjustable  Collar,  for  three-quarter  inch  arbor.  Fig.  4.  Three-quarter  inch 
Cutter  Sleeve,  with  adjustable  stepped  collar,  for  holding  cutters  of  one,  one  and 
one-eighth  and  one  and  one-quarter  inch  bore,  of  any  length  up  to  five  inches. 
Fig.  5.  One-half  inch  Cutter  Sleeve,  with  adjustable  stepped  collar,  for  cutters  of 
five-eighth,  three-quarter  and  seven-eighth  inch  bore,  and  up  to  three  and  one-half 
inches  long.  Fig.  6.  One-half  inch  Cutter  Arbor.  Fig.  7.  One-half  inch  Adjustable 
Collar,  for  one-half  inch  arbor.  Fig.  8.  Face  Mill  Stud,  to  be  used  on  grinding  table. 
Fig.  9.  Cutter  Stud,  for  use  in  universal  head.  Fig.  10.  Socket,  for  grinding  small 
end  mills.  Figs,  n  and  12.  Special  Finger  Attachment,  for  grinding  end  mills. 
Fig  13.  Universal  Finger  and  Holder,  for  general  use  Figs.  14,  15  and  16.  Three 
Arbors,  with  three  styles  of  emery  wheels.  Fig.  17.  1+arge  emery  wheel,  for  rear 
end  of  spindle.  Fig.  18.  Universal  Cutter  Head,  for  use  on  the  grinding  table.  Fig. 
19.  Arbor  Socket.  This  socket  is  fitted  with  the  Gai  vin  and  B.  &  VS.  taper.  Fig.  20. 
The  only  wrench  used  on  the  machine.  Fig.  21.  Crank  Wrench,  for  the  grinding 
table. 


GRINDING. 


257 


Illustrations  Shozving  Various  Work  Performed  on  a  'Different 
Type  of  Universal  Cutter  and  Tool  Grinder. 

In  the  following  pages  will  be  found  a  series  of  illustrations 
showing  some  of  the  many  kinds  of  work  for  which  a  Garvin 
universal  cutter  and  tool  grinder  is  adapted,  also  showing  how  to 
set  the  machine  for  doing  this  work.  As  a  decided  advantage 
over  some  machines,  one  can  grind  all  work  (except  small-end 
mills)  with  the  universal  finger  holder  attached  to  and  adjustable 
with  the  extended  spindle-bearing,  thus  avoiding  the  accurate 
adjusting  of  the  cutter-tooth  with  the  line  of  feed,  which  is 
essential  where  the  finger,  or  tooth-rest,  moves  with  the  work. 
This  construction  also  permits  of  a  very  fine  adjustment  of  the 
finger,  which  is  obtained  by  slightly  loosening  the  clamp  and 
gradually  swinging  the  entire  finger-holder  away  from,  or  in 
toward  the  wheel,  thus  obtaining  a  greater  or  less  amount  of 
backing-off  to  the  teeth,  as  may  be  required. 

In  all  cases  the  face  of  the  finger  should  be  placed  parallel 
with  the  tooth  of  the  cutter  and  point  against  the  direction  of 
the  wheel,  as  the  spindle  is  run  in  one  direction  only. 

When  using  the  finger  the  stops  on  the  grinding-table  should 
be  set  so  as  not  to  allow  the  tooth  to  pass  out  of  engagement  with 
the  finger.  At  the  beginning  of  the  stroke  the  tooth  should  only 
engage  with  the  spring-pawl  of  the  finger,  which  will  allow  the 
•cutter  to  be  turned  around. 

Fig.  185.     Grinding  the  sides  of  face  or  straddle  mills.     The 


FIG.   185. — GRINDING  SIDE   OF   A  STRADDLE 


HARDENING;    TEMPERING   AND   ANNEALING. 

cutter  is  held  directly  on  the  table  and  revolved  on  the  face  mill 
stud  (Fig.  8). 

Fig.  186.     Grinding  the  reverse  side  of  the  same  face  mill; 


FIG.   1 86. — GRINDING  THE  REVERSE  SIDE  OF  A  STRADDLE   MILL. 

no  change  in  adjustment  has  been  made,  only  the  sliding  plat- 
form has  been  moved  on  the  knee. 

Fig.  187.  Grinding  the  face  of  a  straddle  mill,  carried  on  a 
stud  in  the  universal  cutter  head  (Figs.  9  and  18)  ;  the  grinding 
table  being  locked. 


FIG.   187. — GRINDING  THE   FACE   OF  A  STRADDLE   MILL. 


GRINDING. 


259 


Fig.  1 88.  Grinding  a  spiral  tooth-cutter,  carried  on  one  of 
the  sleeves  (Figs.  4  or  5)  which  is  made  to  slide  on  the  arbor 
between  the  head  and  the  adjustable  collar;  the  grinding  table 
locked  by  gib  binder. 

Fig.  189.  Grinding  a  bevel  cutter,  placed  on  the  cutter-stud 
(Fig.  9)  ;  clamped  at  the  proper  angle  in  the  universal  cutter 
nead ;  the  table  moved  between  stops. 


EIG.  188. — GRINDING  A  SPIRAL  TOOTH  CUTTER. 


FIG.  189. GRINDING  A   BEVEI,   CUTTER. 


260 


HARDENING,    TEMPERING    AND   ANNEALING. 


Fig.  190.  '  Sharpening  a  tap  held  in  the  reamer  centers,  which 
are  carried  in  the  universal  cutter  head. 

Fig.  191.  Grinding  a  taper  reamer  in  a  manner  which  pro- 
cures a  straight  backing  off  to  the  teeth. 


FIG.   190. — SHARPENING  A  TAP  ALONG  ITS  FLUTES. 


FIG.   191. — GRINDING   A   TAPER   REAMER   WITH   A   STRAIGHT 
BACKING   OFF. 


GRINDING. 


26l 


Fig.  192.  Grinding  a  taper  reamer  so  as  to  produce  a  shear 
form  of  cutting  edge. 

Fig.  193.  Grinding  the  face  of  a  small  end  mill,  held  in  the 
end  mill  fixture  (Fig.  10)  using  the  special  finger-holder  (Figs. 
ii  and  12). 


FIG.     192. — GRINDING  A   TAPER   REAMER  WITH  A  SHEAR 
BACKING   OFF. 


FIG.   193. — GRINDING  THE  FACE  OF  A  SMALL  END  MILL. 


262 


HARDENING,    TEMPERING    AND    ANNEALING. 


Fig.  194.  Grinding  the  sides  of  an  end  mill,  using  the  same 
fixtures. 

Fig.  :95-  Grinding  the  face  of  a  double  end  butt  mill  on  its 
arbor  and  placed  in  the  arbor  socket  (Fig.  19).  A  light  applica- 
tion of  oil  will  produce  the  proper  tension  in  the  socket. 


FIG.   194. — GRINDING  THE   SIDES   OF  AN   END   MILL. 


FIG.   195.— GRINDING   THE   FACE    OF   A   DOUBLE   END   BUTT   MILL. 


GRINDING.  263 

Fig.  196.  Grinding  the  bevel  corner  on  a  double  end  butt 
mill. 

Fig.  197.  Grinding  a  gang  of  mills  without  removing  them 
from  their  arbor,  which  is  placed  in  arbor  socket  (Fig.  19). 


FIG.   196. — GRINDING   THE   BEVEL  CORNER   ON   A   DOUBLE   END 
BUTT   MILL. 


FIG.   197. — GRINDING   A   GANG   OF   MILLS   ON  THEIR   OWN   ARBOR. 

Fig.  198.     Grinding  an  inserted  tooth  mill. 
Fig.    199.     Grinding  a  die  in  its  bolster  bolted  to  grinding 
table. 


264  HARDENING,    TEMPERING    AND   ANNEALING. 


FIG.   198.— GRINDING  AN  INSERTED  TOOTH   Mil,!,. 


FIG.   199.— GRINDING   A   DIE   IN   ITS   BOLSTER. 


GRINDING.  265 

Fig.  200.     Grinding  a  snap-gage  in  a  vise  bolted  to  the  grind- 
ing table.    All  kinds  of  surface  work,  such  as  straight  edges,  snap 


FIG.  2OO. — GRINDING  A  SNAP  GAGE. 

gages,  punches,  calipers,  test  blocks,  etc.,  may  be  easily  and  quickly 
ground  in  this  fixture. 

Emery  Wheels — Their  Use. 

The  emery  wheel  consists  of  grains  of  emery  and  a  com- 
position called  the  texture  which  binds  these  grains  together. 

In  regard  to  the  size  of  the  grains  the  wheel  is  said  to  be 
fine  or  coarse  in  grade.  In  regard  to  its  texture  it  is  called  hard 
or  soft. 

To  distinguish  the  grades,  they  are  numbered  from  the  di- 
mension of  the  meshes  through  which  the  grains  pass. 

Thus  grade  10  means  that  the  distance  between  the  wires  of 
the  mesh  is  10  to  the  inch. 

Some  of  the  substances  used  to  hold  the  grains  of  emery 
together  are  hard  rubber,  shellac,  ordinary  glue  and  a  mixture  of 
linseed  oil  and  litharge. 

The  relative  hardness  of  the  texture  is  indicated  by  letters. 
Thus,  A  indicates  a  soft  wheel ;  B,  a  harder  wheel ;  M,  medium 
wheel,  and  so  on. 

The  vitrified  emery  wheel  is  made  with  a  cement  which  con- 
tracts slightly  while  cooling,  leaving  small  pores  or  cells  through 
which  water  introduced  at  the  center  is  thrown  to  the  surface  bv 


266  HARDENING,    TEMPERING    AND   ANNEALING. 

centrifugal  force.  This  flow  of  water  operates  to  carry  off  the 
cuttings  and  the  detached  emery. 

The  grade  and  texture  of  the  wheel  in  certain  kinds  of  work 
is  fairly  within  the  following  limits : 

Wheels  of  coarse  grain  and  hard  texture  are  suitable  for 
rough  grinding  such  as  the  smoothing  down  of  protuberances 
and  in  other  rough  work  in  which  accuracy  and  finish  are  not 
required. 

Wheels  having  medium  grains  and  hard  texture  are  service- 
able in  grinding  lathe  tools,  for  gumming  saws,  etc. 

Wheels  with  medium  grains  and  soft  texture  are  suitable  for 
free  cutting  on  broad  surfaces  of  iron,  steel  or  brass. 

Wheels  with  fine  grain  and  soft  texture  are  suitable  for  grind- 
ing fine  tools,  such  as  milling  machine  cutters  for  which  the 
duty  is  light,  but  the  demand  for  accuracy  imperative. 

One  of  the  important  conditions  of  accuracy  is  that  the  wheels 
vary  in  the  least  possible  degree  in  shape  or  diameter  from  start 
to  finish  in  a  series  of  cuts. 

The  wheel  with  fine  grain  and  hard  texture  is  suitable  for 
smooth  grinding  on  soft  metals  such  as  cast-iron  or  brass. 

A  wheel  glazes  or  gums  if  its  grains  are  held  too  long  by  its 
texture. 

The  ideal  duty  of  a  wheel  consists  in  having  its  grains  dis- 
placed as  soon  as  they  become  unfit  for  further  service. 

As  the  wheel  in  use  wears  out  of  true,  it  can  be  trued  by  a 
little  black  diamond  point,  and  if  very  accurate  grinding  or  a  fine 
finish  is  required,  the  diamond  should  be  carried  across  the  sur- 
face of  the  wheel  by  the  long  slide. 

If  it  is  required  to  do  heavy  cutting,  the  emery  wheel  should 
be  trued  at  a  comparatively  slow  speed. 

If  the  wheel  becomes  glazed,  its  surface  may  be  improved  by 
a  coarse  file  or  a  piece  of  pumice  stone. 

Emery  wheels  should  be  kept  clean  and  free  from  oil,  and 
should  not  present  more  than  1-16  to  ^  of  an  inch  to  the  surface 
of  the  work.  This  provision  is  particularly  applicable  to  cup- 
shape  wheels. 

If  it  is  desired  to  put  an  exceedingly  fine  finish  on  such  work 
as  arbors,  spindles,  standards,  etc.,  after  they  have  been  ground 
true,  a  wheel  of  80  or  100  grade  emery,  with  not  more  than 
Y&  inch  face,  should  be  used  for  taking  this  finishing  cut. 

However,  very  finely  finished  surfaces  can  be  obtained  with  a 


GRINDING. 


267 


wheel  as  coarse  as  40  grade  emery,  if  the  work  is  passed  very 
slowly  across  the  face  of  the  wheel  and  the  wheel  allowed  to  cut 
but  slightly. 

In  regard  to  finish,  it  is  to  be  observed  that  the  harder  the 
substance  to  be  ground  the  coarser  must  be  the  grade  of  the 
wheel. 

Thus  the  finishing  of  steel  requires  a  coarser  grade  of  wheel 
than  the  finishing  of  copper. 

If  a  wheel  is  too  hard  for  the  substance  it  is  cutting,  it  may 
heat  or  chatter;  this  can  be  obviated  somewhat  by  diminishing 
the  width  of  the  cutting  surface,  but  it  is  much  better  to  use  a 
softer  wheel  and  full  width  of  cutting  surface. 

As  a  rule  a  soft  wheel  can  be  run  more  rapidly  than  a  hard 


APPROXIMATE 

SPEEDS  FOR 
EMERY  &  POLISHING  WHEELS 


600 


400 


10      12       14        16       1R       20      22      24       26       28      3O       32      34      36 
INCHES  DIAMETER  OF  WHEEL 


FIG.    20T. — DIAGRAM  FOR   DETERMINING  SPEEDS   OF    EMERY 


268  HARDENING,    TEMPERING    AND   ANNEALING. 

one  without  changing  the  temperature  of  the  work.  Accord- 
ingly there  is  an  advantage  in-  two  speeds  for  the  emery  wheel 
spindle. 

For  internal  grinding  the  wheel  should  be  softer  than  for 
external  grinding,  and  the  work  should  revolve  so  as  to  give  the 
wheel  opportunity  to  do  its  work. 

There  can  be  no  hard  and  fast  rules  for  the  speed  of  emery 
and  polishing  wheels  since  there  is  so  great  a  variety  in  the 
nature  of  the  work  to  be  done,  but  a  peripheral  speed  of  about  a 
mile  a  minute  for  ordinary  emery  wheels  is  commonly  regarded 
as  good  practice.  For  water  tool  grinders  the  speed  is  usually 
about  two-thirds  that  of  dry  grinders  while  on  the  other  hand, 
polishing  wheels  are  generally  run  at  about  one  and  one-half, 
and  buff  wheels  at  twice  the  speed  of  dry  grinders. 

The  diagram,  Fig.  201,  affords  a  convenient  means  for  deter- 
mining the  revolutions  that  will  give  the  above  speeds  and  will 
be  preferred  by  many  to  a  table  of  figures.  It  is  necessary  only 
to  trace  a  vertical  line  from  the  figure  representing  the  diameter 
of  the  wheel  to  the  proper  curve  and  from  the  intersection  point 
to  trace  a  horizontal  line  to  the  figure  which  will  give  the  revolu- 
tions per  minute. 


TABLE  OF  ARTICLES  MADE  FROM  CRUCIBLE  STEEL, 

GIVING  ABOUT  PERCENTAGE  OF  CARBON 

THEY    SHOULD    CONTAIN. 

A. 

Carbon. 

Arbor,    saw    •  • 0.60  to  0.70 

Auger,    salt 0.70  to  0.80 

Auger,    wood 0.70  to  0.80 

Axe     i. 20 

Axe,    broad    •  • 1.15 

Axe,    overcoat     1.15 

Axe.    stone 0.80  to  0.85 

B. 

Ball    bearing    1 .20 

Ball  bearing  plates 1.15 

Back,    butcher    0.80  to  0.90 

Barrel,   gun 0.60  to  0.70 

Bits,  auger    0.50  to  0.65 

Bits,    axe .  i.io  to  1.15 

Bits,  channeling  machine    1.15 

Bits,    jointer 1.20 

Bits,   mining    0.80 

Bits,    saw • 0.80 

Bits,    scarf    1.22 

Bits,   tong 1.15 

Bits,  well,  for  stone  drilling 0.80  to  0.84 

Bits,  artesian  well -0.80  to  0.84 

Bites,    plier i.oo  to  i.io 

Blade,    table     0.70 

Blade,    knife    -. 1.15 

Blade,    pocket    0.90 

Blade,   reamer 1.20  to  1.22 

Blanks,   milling  cutter    1.15 

Bolts,    set    •  • 0.60  to  0.70 

Bushing,    spring     0.80 

C. 

Canes  for  hitting  and  missing  devices  on  gas  engines 0.80 

Carriers,    gun 0.60  to  o./o 

Carver    i.oo  to  i.io 


2/O  HARDENING,    TEMPERING   AND    ANNEALING. 

Carbon. 

Centers,    lathe 0.80  to  0.90 

Chisels  for  cutting  files 1.20 

Chisels,   chipping .        i.io 

Chisels,   clay    0.80  to  o.<x> 

Chisels    for    hot    work. 0.60  to  0.70 

Chisels,    railroad   track 0.85 

Chisels,  blacksmiths'   cold 0.85 

Chisels,   stone  cutters' 0.80  to  0.85 

Chisels,   wood   working    1.20  to  1.22 

Chisels,    brick 0.60  to  0.70 

Claw  bars    (pulling  spikes)    0.65  to  0.75 

Cone,    bicycle 0.70  to  0.80 

Creaser    1.20  to  1.25 

Cruciform,    drill 0.95  to  i.io 

Cups,  boiler  makers' 0.60  to  0.70 

Cutters,    flue    .  . 1.20  to  1.25 

Cutters,   glass    .  .  1.20  to  1.25 

Cutters,    milling     . . 1.20  to  1.25 

Cutters,    nail    '. 1.20  to  1.25 

Cutters,    corn   stalk 0.80  to  i.oo 

Cutters,    pipe    1.20  to  1.20 

Cutters,  tong   1.20  to  1.22 

D. 

Dies,   bolt    0.60  to  0.70 

Dies,  blanking    (bottom  dies) 0.85  to  0.90 

Dies,    cartridge    shell 1.20  to  1.22 

Dies,    lever   link    0.85  to  0.90 

Dies,    cold    heating    1.15 

Dies,    cutlery 0.80  to  0.85 

Dies,    envelope    1.15 

Dies,    drop    forging 0.85  to  0.90 

Dies,  drop  forging,  for  making  table  knives 0.68  to  0.78 

Dies,    hammer     0.67  to  0.78 

Dies,   horseshoe    (cold   punching)  . 1.20  to  1.22 

Dies,    glove    0.85  to  0.90 

Dies,    nail 1.15 

Dies,    paper   cutting    1.15 

Dies,    pipe 1.15  to  1.22 

Dies,    rivet     0.60  to  0.70 

Dies,    shoe 0.70  to  o.8e 

Dies,    silver    spoon    0.85  to  0.90 

Dies,    silversmith^' 1.15 

Dies,    tong i.io  to  1.18 

Dies,  wire  drawing   1.20  to  1.22 

Dies    for    pointing    machine 1.15 

Dies  for  manufacture  of  files. 0.67  to  0.78 


TABLE    OF   ARTICLES    MADE    FROM    CRUCIBLE    STEEL.  2JI 

Carbon. 

Digging  bars    0.85  to  0.90 

Dog,  cant 0.90  to  i.oo 

Drills  for  drilling  tool  steel  shear  knives 1.15  to  1.20 

Drills  for  boring  out  shotgun  barrels- i.io 

Drills,    star i.io 

Drills,   quarry i.io  to  1.18 

Drills,    twist    1.20  to  1.22 

Driver,    screw    0.60  to  0.70 


E. 

Edge,    straight 1.05  to  1.12 

Expander  sections    1.20  to  1.22 


F. 

Facing,  anvil    0.85  to  0.90 

Feather 0.60  to  0.70 

File,    cabinet    1.20  to  1.25 

File,  cant  saw • 1.25  to  1.30 

File,   Great  American  cross  cut 1.25  to  1.30 

File,    pillow     •• 1.25  to  1.30 

File,  slim  taper  1.25  to  1.30 

Fork 0.90  to  i.io 

Fork,    carver    0.58  to  0.62 

Furnace    bars 0.60  to  0.70 

Flatters    0.60  to  0.70 

G. 

Glut     0.60  to  0.70 

Grab 0.70  to  0.90 

Grips  in  tube  works 0.85  to  0.90 

H. 

Hammer,   bush 1.25  to  1.30 

Hammer,   blacksmiths'    0.67  to  0.78 

Hammer,  bush  for  granite 1.15 

Hammer,    machinists'    0.90  to  i.oo 

Hammer,   nail   machine 1.05  to  i.io 

Hammer,  peen  1.15 

Hammer,    pneumatic • 0.60  to  0.70 

Hammer,  ball  peen    0.80  to  0.85 

Hardies     0.60  to  0.70 

Hatchet     1.15  to  1.22 

Hoe     ......                               0.85  to  o.' yo 


272  HARDENING,    TEMPERING    AND    ANNEALING. 

Carbon. 

Holders,  tool 0.85  to  0.90 

Hook,  cant   0.85  to  0.90 

Hook,  cant,  for  hammer  dies  •  • 0.68  to  0.78 

Hook,  grass   0.60  to  070 

Hobs,  for  dies    0.85  to  0.90 

J. 

Jar 0.73  to  0.78 

Jaw,    chuck    0.85  to  0.50 

Jaw,   gripping 0.85  to  0.90 

Jaw,    vise 0.85  to  0,90 

Jaw  for  pipe  machine    1.15 

Jaw,    wire   puller. i.io  to  1.18 

K. 

Key  for  hammer 0.75  to  0.80 

Knife,    belt 0.80  to  0.85 

Knife,    blade    • i.oo 

Knife,    scarring    0.90  to  0.95 

Knife,    corn 0.80  to  i.oo 

Knife,    draw     1.20  to  1.22 

Knife,    envelope 1.20  to  1.22 

Knife,  hog   1.15 

Knife,  machine 1.20  to  1.22 

Knife,   paper 1.15 

Knife,  pug  mill 1.05  to  I.TO 

Knife,  shear   . 0.85  to  0.90 

Knife,    whittler     1.15 

Knife,  wood  working 1.15  to  1.20 

Knife,    carver .        i.oo 

Knife,    putty 0.90  to  i.oo 

Knife,  straw  cutter 0.80  to  0.90 

L. 

Lining    for    brick    dies 1.20  to  1.25 

Links,  valve ^ 0.60  to  0.70 


M. 

Magnet  for  telephones i.io  to  1.17 

Magnet 1.23  to  1.25 

Mandrel     1.05  to  1. 10 

Mauls 0.65  to  0.75 

Mauls,    wood    choppers' 0.70  to  0.75 

Molds,    carbon 0.87  to  0.9.5 


TABLE    OF    ARTICLES    MADE    FROM    CRUCIBLE    STEEL.  273 

Carbon. 

Molds,    brick    0.80  to  0.90 

Machinery,    crucible 0.55  to  0.65 

Mattock 0.60  to  0.80 

Mower,    lawn    i.oo 


N. 
Nut  cracker  and  pick 0.70  to  0.73 

P. 

Pick 0.70  to  o.So 

Pick,  mill 1.20  to  1.22 

Piercers  for  nail  machine   i.io 

Pinch    bars 0.75  to  0.85 

Pin,    crank 0.55  to  0.65 

Pin,    eye .  0.75  to  o.So 

Pin,    drift 0.60  to  0.70 

Pin,    expander i.oo  to  i.io 

Pin,    lever    1.05  to  i.io 

Pitching    tool 0.80  to  0.85 

Pivot 1.05  to  i.io 

Planer,  stone 0.70  to  0.80 

Planer,    wood. 1.15 

Plates,    guard. 0.90  to  i.oo 

Plates   for  brick   dies 0.85  to  0.90 

Plate,   throat,    for   hog 0.85  to  0.90 

Plate,    tool 0.90  to  0.95 

Plow,  crucible,  for  bicycle  road  scraper 0.85  to  0.90 

Plow,  ice 0.80  to  0.85 

Plug    0.60  to  0.70 

Plungers    for   bolt    machine «  -0.60  to  0.70 

Plungers    0.85  to  0.90 

Pliers 0.85  to  0.95 

Point     -. 0.85  to  0.90 

Point,    clay   pick 0.85  to  0.90 

Point,    piercing 1.40  to  1.50 

Puller,    nail 1.20  to  1.22 

Punch,    cartridge    shell 1.20  to  1.22 

Punch,   hot   work 0.85  to  0.90 

Punch,   file  blank 1.20  to  1.22 

Punch,   skate   blade 0.85  to  0.90 

Punch,    washer 0.80  to  0.88 

Punch,    oil    cloth 0.85  to  o.oo 

Punch,    blacksmith 0.80  to  0.85 

Punch,    railroad    track •  • 0.85 


274  HARDENING,    TEMPERING   AND    ANNEALING. 

R. 

Carbon. 

Racer,    ball 0.90  to  0.95 

Rake   1.15  to  1.25 

Reins,  tong 0.60  to  0.70 

Ring 0.85  to  0.90 

Rods,    bench 0.66  to  0.76 

Rods,    piston 0.70  to  0.80 

Rolls,    expander •  . 1.05  to  i.io 

Rolls  for  hitting  and  missing  device  on  gas  engine 0.85  to  0.90 

Rolls,  loom  mill 0.55  to  0.65 

Rolls  for  holding  steel  scrap  on  wooden  shovel  handles 0.85  to  0.90 


S. 

Saws;  circular .  • 0.80  to  0.90 

Saws  for   sawing   steel 1.60 

Saws,   cross   cut •  . 0.85  to  i.oo 

Saws,    band •  • .  .0.68  to  0.75 

Saws,  drag 0.95 

Saws,    pit •  • '. 0.85  to  i.oo 

Saws,    mill 1.25  to  1.30 

Saws,    gang •  • 0.90  to  i  .00 

Scarf •  • 1.20  to  1.25 

Scrapers,  road 0.60  to  0.70 

Scrapers,    tube .  • 1.20  to  1.22 

Screws   on  elevators 0.85  to  0.90 

Screws,     set 0.65  to  0.75 

Sets,    rivet. 0.65  to  0.75 

Sets,  button    0.65  to  0.75 

Scythe    edge •  • 1.20  to  1.22 

Shafts  for  skull   cracker  crane 0.60  to  0.70 

Shafts,  quick  running  motor 0.55  to  0.65 

Shear,    pruning 0.85  to  0.93 

Shear,   sheep 0.96 

Shim 0.60  to  0.70 

Skate 1.15 

Sledge    0.65  to  0.75 

Slides 1.20  to  1.22 

Snaps     0.60  to  0.70 

Spindle 0.55  to  0.65 

Spring,    common    locking 1.20  to  1.25 

Spring,     knotter . 1 .20  to  1 .25 

Spring,    railroad 0.90  to  i.io 

Spring,    locomotive 0.90  to  i.io 

Steel,    carver 1.40 

Stretching   bars i  .27 

Swages,  saw   0.85  to  0.90 


TABLE    OF   ARTICLES    MADE    FROM    CRUCIBLE    STEEL.  275 

T. 

Carbon. 

Taps     1.20  to  1.22 

Taps,    nut 1.15 

Taps,     spindle 1.20  to  1.22 

Teeth,    car   wheel 0.85  to  0.90 

Teeth,    dredge    bucket 0.75  to  0.83 

Teeth,     shovel 0.60  to  0.70 

Teeth,  saw   0.85  to  0.90 

Tip    •  • 0.70 

Tongs     0.90  to  0.95 

Tongs,    ingot 0.85  to  0.95 

Tongs,    skidding 0.85  to  0.90 

Tool  for  turning  hard  rubber 1.05 

Tool  for  reaming  inside  of  guns 1.05  to  1.12 

Tools,    bricklayers'     0.90  to  0.95 

Tools,    blacksmiths' 0.60  to  0.70 

Tools,    moulders' 1.25  to  1.30 

Trowel     •  • 0.40  to  0.45 

V. 
Vises     0.90  to  0.95 


W. 

Wedge,    crucible 0.66  to  0.76 

Wedge,    stone 0.65  to  0.70 

Wedge    for   breaking   frozen    ore .  • 0.60  to  0.70 

Wreath,    crucible 0.66  to  0.76 

Wrenches o.Ro  to  0.90 

Wrenches,   track 0.80  to  u.  ;<• 


INDEX. 


Accommodate     expansion 98 

Accomplishing  fine  results  with  self- 
hardening    steel 27 

Accurate  sectional  casehardening...    139 

Acid,   improved  soldering 196 

Acme   standard  thread 222 

Actual   pressure   against   tool 115 

Adoption    of    nickel    steel    for    forg- 

ings     194 

Advantage  derived  from  the  use  of 

gas   as   a   fuel 53 

Advantage  in  the  use  of  the  tools..    116 

Advantage   of  the   method 148 

Advantage   of  nickel   steel  for   forg- 

ings     194 

Advise   the  use  of  cutters  of.  small 

diameters     115 

Agitating  contents  of  the  bath....    103 

Air  hardening  process 22 

Air  tempering  furnace 61 

Allowance  desired  in  machining.  .  .  .    188 

Allowing  die  to  cool  to  a  black 168 

Aluminium,  lubricant  for  working.  .    196 

Aluminium,    solder   for 197 

America,  Crucible  Steel  Company  of     34 
America,    high-grade    steel    forgings 

in    176 

America,    steel   produced    in    by   the 

crucible    method    34 

American   drill   rod 14 

Augular   cutters,   grinding 232 

Angular  type  of  milling  cutter.  .  .  .    154 
Animus     referred     to     by     Admiral 

Evans     178 

Annealed  die  and  tool  steel 21 

Annealing    38 

Annealing  a  small  quality  of  steel.      43 

Annealing  box  for  small  parts 39 

Annealing  chilled  cast  iron  dies  for 

drilling     43 

Annealing,  furnace-packing  the  cast- 
ings           45 

Annealing,   how  to  heat  for 37 

Annealing  iron  castings 137 

Annealing  in  the  charcoal  fire....        38 
Annealing  low  carbon  steel  bars.  .  .      136 

Annealing  ovens,   heating  the 47 

Annealing  steel  in  the  open  fire.  .  .        43 
Annealing,  straightening  and  finish 

ing  malleable  castings 46 

Annealing,  the  effects  of  water.  .  .        40 
Annealing,  the  proper  heat  for ....        37 

Annealing,  water   39 

Annealing   white   or   silver   iron.  ...    44 
Anti-friction  alloy  for  journal  boxes  197 
Apparatus     used     in     the     Taylor- 
White  process 116 

Appearance    of    fractures    of    high- 

gi-ade  steel  of  various  hardness     15 
Appreciate   the   advantages   of   steel 

forgings 179 

Approximate    cutting   speeds 27 

Approximate   speeds   for   emery   and 

polishing   wheels    26 

Area   of   a   hexigon 207 

Articles    made    from     crucible    cast 

steel    ...  34 


Articles,    hardening    l<mg   thin 

Articles,    tempering    thin 

Ai-t  of  forging  with  drop  hammers. 

Art  of  steel  treatment,  how  to  in- 
struct in  the  

Arts,    Society    of ;  •  *  *  i 

Arranged  alphabetically,  table  ot 
tempers  

Asbestos    washers    •  •••••• 

Ascertaining  the  size  of  pulleys  for 
given  speeds  •  •  •  • 

Assorted  stock  of  metal  for  drop 
forgings  

Attachment    for    surface    grinding.  . 

Attainment  of  satisfactory   results. 

Attention  to  the  proper  selection  ot 
steel  in  diemaking  

At  bottom  of  thread,  decimal  con- 
stants for  finding  diameter .... 

Authority    on    the    subject 

Average  time  required  to  machine 
fourteen  sheaves 

Average   speeds   for    cutting    drills. 

Axial  type  of  milling  cutter 


Babbiting     

Baking  enamels  and  vulcanizing  rub- 
ber,  table  of  suitable  tempera- 


122 
122 

187 

31 
197 

125 

112 

195 

191 
251 

18 

14 

210 
95 

114 
223 
154 


196 


tures    for    casehardening,    core 
ovens,     drying    kilns 127,   128 


Barrel  heating  machine  for  harden- 
ing and  tempering  balls,  saw 
teeth,  screws,  etc 

Bath,    the    

Bearing  rings,  hardening  five-inch 
thrust  

Belts,   horse  power   of 

Bench  forge    

Bessemer   steel,   casehardening 

Bethlehem    Steel    Company 

Bevel  edges,  how  to  grind  a  slit- 
ting knife  with 

Binds   the    grains   together 

"Biting    in"     

Blanking  die,  hardening  a 

Blanking  or  cutting  dies,  harden- 
ing large  

Blazing    off    springs 

Blind  to  the  temper  colors  of  steel . 

Blistering,  preventing  it  while  heat- 
ing   

Blows  water   from   the  teeth 

Blue,  to  draw  small  steel  parts 
to  a  

Board  with  stripes  of  paint  and 
names  of  steels  

Boiled    water    

Bone,   charring  the 

Bone,  to  char  the 

Borax  of  commerce 

Both  die  and  punch  should  be 
hard  *. 

Brands  of  stoel  in  general  use.  .  .  . 

Brands  suitable  for  special  classes 
of  sheet-metal  working 

Brass   articles,    lacquer   for 

Break   like   glass 


75 
135 

131 
225 
65 
133 
113 

245 
265 
204 
166 

173 
161 
176 

142 
154 

161 

14 

96 
134 
134 
175 

174 

18 

14 
206 

157 


INDEX. 


2/7 


Breaking  down  point 113 

Bringing  slowly  to  the  required 

heat  143 

Buggy  springs,  to  weld 194 

Bulky  portion  contracts  away  from 

the  frailer  portions 168 

Bunsen  burner  122 

Bureau  of  Steani  Engineering.  .  .  .  194 

Burning  off  not  necessary 120 

Bushing,  how  to  grind  a  hardened 

drilling  jig    243 


Cake    of   soap,    hardening    in Ill 

Calculations  for  determining  speeds, 

27,  195 
Capable    of    withstanding    wear....    142 

Capacity  of  steel  to  cut 30 

Capital    steel    18 

Carbon     and     air-hardening     steels 

deteriorate,    when 113 

Careful  in  heating  and  quenching.  .  95 
Careless  and  unequal  hammering.  .  159 

Carnegie     Steel     Company 140 

Casehardening  as  it  should -be  under- 
stood        142 

Casehardening,    accurate    sectional.    139 

Casehardening  tools    129 

Casehardening  cups  and  cones 198 

Casehardening  furnaces    85 

Casehardening  mixture  for  iron.  .  .  141 
Casehardening,  Moxon's  method  for.  141 
Casehardening,  outfit  for  fine  grain.  129 

Casehardening    polished    parts 142 

Casehardening   paste    141 

Casehardening     the     ends     of     steel 

rails     140 

Casehardening,    very   deep 140 

Casehardening    with    kerosene 197 

Casehardening   with   cyanide   of   po- 
tassium        137 

Casting   chain    links 48 

Castings,   annealing  furnaces,   pack- 
ing  the    45 

Castings,   annealing  iron 137 

Castings,     annealing,     straightening 

and   finishing    46 

Cast   iron,   to  harden 141 

Cast    iron,    to    weld 183 

Cast  steel,  composition  for  welding.  183 

Cause   of  cracks   in  dies 167 

Causes    of    failure    in    using    high- 
grade  steel    15 

Causes   the   oil   to   come   in   contact 

with    the    teeth 146 

Chain,    automatic    heating    machine 

for    hardening    85 

Changes  in  the  grain  of  the  metal.     17 
Changes  of  length  produced  by  heat.     32 
Characteristic    appearance    of    frac- 
tures      _ 15 

Charcoal    182 

Charcoal,    annealing    in 38 

Charcoal   and  bone 133 

Charcoal,    bone   and    133 

Charcoal.    Casehardening    cups    and 

cones    in    198 

Charcoal,   flame,   tempering   in 122 

Charcoal   for  heating 100 

Charcoal        made       from       charred 

leather 109 

Charcoal  on  the  top  of  the  lead.  .  .    153 

Charcoal,   the  best 182 

Charcoal,    to   caseharden   with 140 

Charring  the   bone    134 

Cheapest    drop    forcings 192 

Cheanly    made     cyanide     hardening 

not    138 

Checking  the  temper   Ill 

Chemical   changes   in  clay 132 


Chemical    compounds,    receipts    for. 

Chief  of  Ordnance,   report  of 

Chucking   drills    

Circular  annealing  and  hardening 
furnace  

Circular    forming    tools    

Circulation  of  a  stream  of  water 
upward  

Circumstances  determine  the  amount 
of  shear  to  give 

Citric   acid   crystals    

Classified,    milling    cutters 

Clay,  heat  effects  on 

Cleaning  the   work    

Clearance  on  tools  for  brass 

Closely    controlling    temperature.  .  . 

Coaly    animal    matter    

Coarse  appearance  of  grain 

Coarse    crystalline    section 

Coating  with  tallow    

Coke    suitable    for    hardening 

Collection  of  plain  milling  cutters. 

Collecting  the  segregation  and  pip- 
ing in  the  center 

Collet   spring   chucks,    hardening. .  . 

Colors  from  a  light  straw  to  a  deep 
blue  

Colors  of  steel,  table  of  tempers 
for  tools 

Color  on  steel  simply  an  indication 
of  heat  

Colors,  table  of  temper   

Colors,   tempering  by    

Colt,  Colonel   Samuel    

Combination  gas  furnace  for  gen- 
eral machine  shop  work 

Combined   oil    and    water    method.  . 

Composition   called   the   texture.  .  .  . 

Composition  for  cast  steel,  welding. 

Composition   to    toughen    steel 

Compounds  for  welding  steel 

Consumption    of    oil    small 

Concave  or  straight,  how  to  grind 
milling  cutters  and  metal  slit- 
ting saws  

Condition  to  be  prized  in  steel 

Conditions  of  the  different  sections. 

Confounding  cracks  with  hardening. 

Consequent  contraction  and  expan- 
sion   

Consequent   sudden  chill    

Construction  and  operation  of  barrel 
heating  machine  

Constant  reheating   

Contraction   during  quenching    .... 

Contraction   during   cooling    

Contracting  excessively  in  the  cen- 
ter   

Cooling    ...'...I.'..'.'... 

Cooling  or  quenching   

Coppering    polished    steel    surfaces. 

Copper-over  surface   nicely 

Core  of  tool  left  comparatively 
soft  

Corliss,  George  H 

Cost  and  endurance  of  forging 
dies  

Cost  of  good  steel   

Cost  of  gas  as  compared  with  other 
fuel  

Costly  accidents 

Counterbores,  heating  in  lead 

Counterbores.    clearance   for 

Counterbores.    internally    lubricated 

Counterbores  for  cast  iron  and  steel 

Counterborine:     

Covering  with  clay   

Coyan,  M.  E 

Cracks  in  dies,  their  cause 

Crescent    steel 

Crucible  Steel  Company  of  America. 


124 
108 
198 

81 
203 

162 

174 

96 
154 

32 
135 
204 
116 
142 

23 
182 

43 
100 
144 

180 
112 

136 


117 

128 
117 
187 

54 
146 
265 
183 
184 
183 
121 


252 
17 
16 

167 

168 
112 

77 

99 

99 

180 

172 
136 
100 
196 
196 

149 
177 

190 
13 


53 

24 

106 

?04 

204 

204 

204 

43 

140 

167 

18 

34 


INDEX. 


Crucible     steel,     table     of     articles 
made    from,    giving    percentage 

of  carbon  they  should  contain.  269 

Crucible  cast  steel    176 

Crude  and  obsolete  means  for  heat- 
ing and  cooling   50 

Crude  oil   for  rock  drill   tempering.  120 
Crystallizes    from    shock    or    vibra- 
tion   in   service    182 

Cubic   contents   in   inches   of   a   bar 

of    Iron     207 

Cubic    foot    of    water,    weight    and 

capacity     105 

Cutter  and  tool   grinder    227 

Cutter    bits,     hardening 159 

Cutter    blades    104 

Cutter   for    milling    teeth    in   spiral 

mills     155 

Cutter    lubricant    225 

Cutter  lubricant   for  steel  or  iron.  225 

Cutters  to  remain  in  oil  until  cold.  146 

Cutters,   milling,   their   use 154 

Cutting  and   durability   qualities   of 

steel     30 

Cutting  at  high  speeds Ill 

Cutting  speeds,   table  of 138 

Cutting  speeds  for  cast   iron 27 

Cutting   speeds    for   malleable    iron.  28 

Cutting  speeds  for  steel 30 

Cutting  speeds  for  brass 30 

Cutting   tools,    speeds   for 27 

Cutting   tools,    self -hardening 27 

Cutting    tools,    casehardening 130 

Cutting  thin  stock        174 

Cutting   edges    of   twist    drills...    .  198 

Cutlasses,    tempering   swords   and    .  123 

Cyanide   hardening  furnaces 95 

Cyanide    soap     206 

Cylindrical    casehardening    furnace.  85 

D 

Day,  Mr.  Charles 113 

Dead    cold    157 

Decarbonization     99 

Decarbonized  steel   surfaces    24 

Decarbonizes,   when  steel    52 

Decimal       equivalents       of       milli- 
meters        208 

Decimal    equivalents    of    fractional 

parts  of  inch    209 

Deep     blue,     colors     from     a     light 

straw  to  a    136 

Deep   casehardening,   very 140 

Deep    recesses,    work    with 95 

Defects   running   through    center   of 

bars     23 

Defining  the  terms 36 

Definite    degree   of   elasticity,    hard- 
ening steel  to   31 

Degree    to    which     the    article    ex- 
pands         99 

Degrees  of  softness  down  to  a  blue 

tinged    with    green    117 

Degrees   of  softness  below  that   de- 
noted by  thermometer    117 

Delicate  pieces,  dipping   1 

Desirable  condition  in  drop  dies.  ...  164 

Desirable   tendency    158 

Determining    the    correct   hardening 

process     15 

Deterioration    due    to    heating 21 

Device  for  hardening  bushings,  shell 

reamers,  etc Ill 

Diamond  tool  holder 253 

Die-blank,    reannealing     170 

Die  steel    14 

Die  steel,   hardening  poor 172 

Dies  cracking  while  in  the  forge.  .  .    168 
Dies,    drop,    hardening    and   temper- 
ing         163 


Dies  from  forgings  of  wrought  iron 

and    steel    162 

Dies  hardening  fluids  for   172 

Dies  hardening  and  tempering  large 

cutting     173 

Dies    spoiled    through    carelessness 

and    inexperience     167 

Dies  used  for  special  drop  forgings .  187 
Dies  for  regular  shaped  blanks ....  129 
Difference  between  hard  steel  and 

tough    steel     93 

Different   methods   of   packing  cast- 
ings in  pots    45 

!  Different  quenching  baths,   their  ef- 
fects  on   steel    96 

|  Difficulties  encountered  in  introduc- 
ing high-grade  steel 181 

j  Diminishing  width  of  cutting  face .    267 
i  Dipping  a  long  half-round  reamer.  .    105 
I  Dipping  at  an  angle  of  about  20  de- 
degrees     105 

fluted   reamers   when  hard- 
ening      157 

Dipping  half-round  or   "gun"   ream- 
ers   when    hardening     105 

i  Dipping  in  a  strong  solution  of  salt 

and  water   96 

Dipping  on  a   rising  heat 18 

Dipping    small    tools    when    harden- 
ing         156 

Dipping  vertically    101  to  109 

Disagreeable    possibility    eliminated.  169 
Discarding  the  color  method  of  tem- 
pering         119 

Distortion  takes  place,   when 97 

Distortion  through  uneven  heating.  97 
Direct  a  stream  of  water  onto  the 

face  of  the  die 164 

Directions  for  annealing  with  gran- 
ulated raw  bone 136 

Directions  for  setting  up  drop  ham- 
mers         192 

Double   face   mill    146 

Doubtful   steel,   to  anneal    43 

Drawbacks    to    the    commercial    use 

of  nickel  steel    194 

Drawbacks  to  the  use  of  aluminum.  197 
Drawbridge  disc  and  similar  work, 

hardening     131 

Drawing    and   forming   dies,    chilled 

iron 43 

Drawing    to    a    temper    of    400    de- 
grees         122 

Drilling  a  large  hole  in  a  spindle.  .  198 
Drilling,  annealing  cast  iron  dies 

for    43 

Drilling   hard   steel,    lubricant    for.    196 
Drilling  or  turning  aluminum,  lubri- 
cant   for    196 

Drill  entered  through  a  bushing.  .  .    199 

Drill    with   one    cutting   edge 199 

Drills  for  brass    198 

Drills  for  standard  pipe  taps,  sizes 

of    218 

Drop  dies,  hai'dening  and  tempering.  163 

Drop  forged  bracket    192 

Drop    forged    crank    shafts    188 

Drop    forged    wrenches    189 

Drop  forged   gear  blank    191 

Drop   forging   plant    186 

Drop  hammers,  forging    185 

Drop    hammers,    directions    for    set- 
ting up  forging   192 

E 

Each  brand  in  separate  rack 14 

FTccentric  ring,  hardening  an 98 

economical  use  of  gas  as  a  fuel..  53 
Economy  in  purchasing  cheap  tool 

steel,    no 113 


INDEX. 


279 


Economy  in  steel}  how  to  obtain...     13 
Economy  in  testing  steel  before  us- 
ing       24 

Effects  of  heat   on   steel 97 

Efficiency   and   judgment    95 

Efforts  of  the  government  to  obtain 

steel  suitable  for  large  guns.  .    177 

Elastic  limit  of  nickel  steel 194 

Eliminating    tendency    to    warp....    112 
Eliminating  the  possibility  of  warp- 
ing         166 

Emery  wheels,  their  use 265 

Empty  crucible  after  using 107 

English  blue 161  I 

English    works    duplicated 179 

Entering    the    die    edgeways Ill 

Entirely  eliminated,  segregation  and 

piping     180 

Equal  sectional  area 98 

Equivalent  measures,   table  of  Eng- 
lish   or   American    (U.    S.) 211 

Establishments    devoted    exclusively 
to    the   manufacturing   of    drop 

forgings    191 

Establishment    where    thousands    of 

dies  are  made  every  year 167 

Evans,    Admiral    Robley    D 178 

Even  grain  and  velvety  appearance.  17 
Even  spacing  instead  of  staggered.  199 

Even    temper    165 

Expansion  of  different  metals ....  34! 
E!xact  knowledge  in  the  matter.  .  .  113 
Exact  degree  of  temper  determined 

by   experiment    118 

Expansion  of  gases   31 

Expansion  of  wrought  iron  for  each 

degree   Fahrenheit 33 

Expansion    unequal     32 

Expansion    reamers     201 

Expert  in  the  art    95 

Experience    in    working    and    using 

the  different  brands    13 

Experience,    skill    and    sound    judg- 
ment           95 

Experience  with  different  grades  of 

steel    13 

Experience   with    crude   oil 120 

Experimental    treatment    15 

Exposing  heated  steel   to  a  current 

of   air    20 

Extensive  experiments  with,  various 

metals     194 

Extensive   use   to   which   drop   forg- 

gings   have   been  put    188 

Extra  cost  of  annealed  steel 14 

Extra   heavy   work,    hardening 131 


Face    milling    large    castings,    steel 

for    27 

Facing     204 

Features,  prominent    227 

Ferris    wheel    shaft    181 

Figuring   cost   of   tools    188 

Figuring  the  surface  speeds  of  emery 

wheels    and    milling    cutters.  .  .    207 

Files,  to  temper  old 160 

Finding    diameter    of    driven 195 

Finding    number    of    revolutions    of 

driver    195- 

Fmding   the   area    of   cylinder.  .      .    206 
Finding  the  capacity  of  a  cylinder 

in  gallons 205 

Fine    grain,    casehardening    for 12T> 

Fine  grain,  compact    129 

Finest    metal    pattern    work 49' 

Finishing     cold,     hammering     hard 

and    18 

Finishing  without  grinding  or  clean- 
ing  198 


Fire  and  heat,   the   hardening 99 

Fire  must  be  free  from  gas 130 

Fire  of  small  soft  coal 10O 

First    advisory    board    for    rebuild- 
ing   navy     178 

First   annealing   does   not   eliminate 

the  liability  of  cracking 168 

Fixed  general   rules 18 

Flange-ended     tubes,     clamping     be- 
tween       156 

"Floating"    reamer    201 

Fluids   for  dies,   hardening 172 

Fluted    cuts    too    shallow    199 

Fluted    reamers,    when    hardening.  .  157 

Flux,   a  good   welding,   for  steel.  .  .  175 

Flux,    French    welding    185 

Flux,  for  soldering  and  welding...  187 

Force    contents    into    hole 154 

Formed   butt   mill 147 

Forge,    bench    65 

Forged,   how  hollow  shafts  are ....  179 
Forged,    steel    for    tools    which    re- 
quire to  be .  176 

Forging,     drop 187 

Forging,    drop    hammers,    directions 

for  setting  up    192 

Forgings    from    steel    of    high    car- 
bon      191 

Forgings  for  cutting  dies 18 

Forgings,  government  use  of  nickel 

steel   for    194 

Forgings    in    America,    high-grade.  .  176 

Forgings,    steel   die 14 

Forging,   heating  steel   for 18,  176 

Forging   plant,    larger   and   superior 

to  any   in   the   world    179 

Forging   to    shape 18 

Formed  type  milling  cutter 155 

Formed    face     mill 147 

Formed  cutters   with  steps 203 

Formulas     for     sharp      V     thread, 
United  States  standard  thread, 

Whitworth  standard  thread  .  .  .  221 

Frequent  renewal   by  forging 99 

From  cast   iron   and  steel,  to  make 

edged  tools    183 

From   steel,   to   remove   scale 197 

From   32   degs.   F.   to  212   degs.   F., 

table   of   expansion 34 

Furnace,   air  tempering    61 

Furnace,     circular     annealing     and 

hardening    80 

Furnace,    cylindrical    casehardening.  81 

Furnace,   lead  hardening    88 

Furnaces,    casehardening 85 

Furnaces,    cyanide   hardening 91 

Furnaces,    muffle 93 

Furnaces,   oil   tempering    81 


Gages,   hardening  ring 156 

Gaging   the  heat   by   thermometer .  .   119 

"Gall"    and    "nerve" 95 

Gang   of   straight   face   milling  cut- 
ters         146 

Gang    of    cutters    for    machining    a 

wide    formed    surface 147 

Gang  punch,  hardening  and  temper- 
ing   a    split    173 

Gas   blast   forges,   their   use 54 

Gas    consumption    53 

Gas,    flame,    tempering    in 158 

Gas     forge     for     knife     and     shear 

blades    64 

Gas  forge   for   small   work 59 

Gear    cutter    grinding 238 

General    directions     252 

General  directions  and  rules  for  the 

hardening  of  steel   97 


280 


INDEX. 


General  matter  relative  to  malleable 
iron  machine  parts  

General  smith  work,  hardening  mix- 
ture for  

Generation  of  steam  when  harden- 
ing   

Getting  rid  of  the  center  of  a  hol- 
low forging  

Glue  to  resist  moisture    

Good  and  uniform  temper   ........ 

Good  weld  between  parts,  neces- 
sary to  have  

Good   welding   flux   for   steel    .  . .  . . 

Good  steel  for  good  tools 

Good  tools,   good  steel  for ...'.'.'. 

Government  blue   

Government  use  of  nickel  steel  for 
forgings  

Grade  and  texture  of  the  wheel .... 

Grade  of  steel  to  use  for  dies 

Gravers,    to    temper    

Grain   rendered   coarse   and   brittle. 

Granulated  charcoal    

Granulated  raw  bone,  directions  for 
annealing  with  

Granulated  raw  bone,  obtaining 
colors  with  

Granulated  raw  bone,  how  to  case- 
harden,  color  and  anneal  with . 

Graphite   crucible    

Great    flexibility    of    steel 

Great  hardness,  testing  for 

Great  ordnance  works  of  the  Bethle- 
hem Steel  Company 

Greatest  uniformity  and  maximum 
results  

Green   coal    

Grinder,  a  small  cutter   

Grinder,  Cincinnati  universal  cutter 
and  tool  

Grinding   angular    cutters 

Grinding,   attachment  for  surface.  . 

Grinding  a  bevel  cutter   

Grinding  a  die  blank  to  the  re- 
quired angle  

Grinding  a  die  in  its  bolster 

Grinding  a  formed  tool  on  its  face. 

Grinding  a  gang  of  mills 

Grinding  a  gage  to  a  given  dimen- 
sion   

Grinding  a  hardened  drilling  jig 
bushing  

Grinding  a  hand  reamer    

Grinding  a  shear  plate    

Grinding   a   straight   edge 

Grinding  a  spiral  mill 

Grinding  a  spiral   tooth   cutter.  .  .  . 

Grinding  a  slitting  knife  with  bev- 
eled edges 

Grinding    a    snap    gage    

Grinding   a    taper    spindle 

Grinding   a  taper   reamer    

Grinding  a  tap  held  in  reamer  cen- 
ters  

Grinding  a  taper  reamer  with 
straight  backed  off  edges 

Grinding  a  taper  reamer  with  shear 
cutting  edges  

Grinding  a  worm   wheel   hob 

Grinding  a  twenty-four  inch  cold 
saw  

Grinding    an    inserted    tooth    mill .  . 

Grinding  broad  surfaces,  wheels 
suitable  for  

Grinding  cutters  of  small  diameters 
and  sharp  angles  

Grinding,   cutter  and  tool 

Grinding  formed  cutters 

Grinding,  general  directions  for.  .  .  . 

Grinding  gear  cutters 

Grinding,   internal    


48 

160 

97 

179 
206 
161 

162 

175 

38 

38 

161 

194 
265 
14 
160 
105 
130 

136 
136 

130 

106 

175 

24 

177 

115 
100 
254 

227 
232 
251 
259 

248 
264 
248 
263 

250 

243 
241 
247 
246 
231 
259 

245 
265 
244 
241 

260 
260 

261 
241 

237 
263 

266 

231 
227 
240 
252 
238 
246 


Grinding  lathe  tools,  wheels  suit- 
able for  26« 

Grinding  milling  cuttere  and  metal 

slitting  saws,  large 23« 

Grinding  mil'ing  cutters  or  saws 

straight  or  concave 252 

Grinding  milling  machine  cutters, 

wheels  suitable  for  200 

Grinding  soft  metals,  wheels  suit- 
able for  260 

Grinding  shell   counterbores    236 

Grinding  side  milling  cutters  with 

a  large  wheel  230 

Grinding,  shapes  and  sizes  of  emery 

wheels  for  tool  228 

Grinding  side  milling  cutters 233 

Grinding  twist   drills    202 

Grinding  reamer  blades  convex ....    199 

Grinding  the  bevel  corner  on  a 

double  end  butt  mill  263 

Grinding  the  face  of  a  double  end 

butt  mill  262 

Grinding  the  face  of  a  small  end 

mill 261 

Grinding  the   sides  of  an  end  mill.    262 

Grinding  the  face  of  a  straddle  mill.  258 

Grinding  the  reverse  side  of  a  face 

mill  258 

Grinding  the  sides  of  a  face  or 

straddle  mill 257 

Grinding,  the  wheels  suitable  for 

internal  268 

Grinding,  the  wheels  suitable  for 

rough  266 

Ground  in  special  machines    174 

Ground  work,  samples  of 229 

H 

Hammer  all  sides  alike   159 

Hammer  directly  over  spot  rest- 
ing on  anvil  123 

Hammering  and  rolling  steel  billets  179 
Hard   or   soft   punches   and   dies .  .  .    163 

Hard  or  soft  wheels    265 

Hard  steel,   lubricant   for  drilling.  .    196 
Hard    steel,     tempering    flat    drills 

for    drilling    160 

Hard    stock,    tempering    flat    drills 

for    160 

Harden  in  bath   with  teeth   up 154 

Hardened    machine    steel    parts,    to 

produce   fine  grain    139 

Hardener    will    be   blamed 175 

Hardening     and     tempering     spring 

collet  spring  chucks    112 

Hardening  and  tempering  drop  dies.  163 
Hardening  and  tempering  large  "cut- 
ting" or  "blanking"  dies 173 

Hardening  and  tempering  mill  picks..  121 
Hardening     and     tempering     milling 

cutters  in  water  and  oil 147 

Hardening    and    tempering,     proper 

equipment  for 52 

Hardening     and     tempering     small 

taps,    knives,   springs,   etc 160 

Hardening      and      tempering      split 

gang    punches     173 

Hardening   and   tempering    springs.    161 
Hardening     and     tempering     round 

thread  dies    Ill 

Hardening    and    tempering,    special 

instructions  for    110 

Hardening  around  a  hole 156 

Hardening  at  different  tempera- 
tures   Ill 

Hardening  a   blanking  die 166 

Hardening  cutting   bits    159 

Hardening  drawbridge  disc  and  sim- 
ilar work  131 

Hardening  extra  heavy  work 131 


INDEX. 


28l 


Hardening  equally  all  through 99 

Hardening  files    108  to  160 

Hardening    five-inch    thrust    bearing 

rings     131 

Hardening    fluids    for    dies 172 

Hardening,    heating   for 18 

Hardening,     heating     in     hot     lead 

for     103 

Hardening    hollow    mills     153 

Hardening  in  clear  oil 173 

Hardening    in    solutions 106 

Hardening,    judgment    and    careful- 
ness  in    95 

Hardening    large    milling    cutters.  ..   143 

Hardening  large  pieces 95 

Hardening  large  dies    162 

Hardening    long    taper    reamers, 

103  to  109 

Hardening   metal    saws 155.) 

Hardening    milling    cutters    in    the 

open    fire     143 

Hardening     mixtures     for     general 

smith    work    160 

Hardening    of    inexpensive    cutting 

tools    118 

Hardening  poor  die   steel    172 

Hardening,    quenching   for 100 

Hardening  ring  gages   156 

Hardening    small    parts     and     long 

thin  parts   104 

Hardening  small  saws    159 

Hardening  successful    38 

Hardening    the    walls    of    a    round 

die    169 

Hardening  steel   by  petroleum 197 

Hardening  thick   round  dies    172 

Hardening   very   small   punches....    171 
Hardening  very  thin  tools  so  as  to 

prevent    warping    158 

Hardening    V    shaped    milling    cut- 
ters     152 

Hardening   shell    reamers,    bushings, 

hobs,    etc Ill 

Hardening,  warping  of  punches  in.  .    171 

Hardening,  warping  of  tools  in 109 

Hastings,   B 120 

Heat    distributed    equally 119 

Heat    affects     center    equally     with 

outside     180 

Heat  effects  on  copper  and  bronze .    119 

Heat  effects  on  clay 32 

Heat,   first  effect  of 31 

Heat,  second  effect  of 34 

Heat,   the    135 

Heat,   the  hardening  fire  and  the.  .      99 

Heating     50 

Heating  according  to  shape 98 

Heating    and    tempering,    effects    of 

slow     97 

Heating,  distortion  through  uneven.     97 

Heating  for  forging   18 

Heating  for  hardening   18 

Heating  furnace,  the  location  of  the     52 

Heating  in  the  open  fire 99 

Heating  in  hot  lead  for  hardening.    106 
Heating  machine  for  hardening  the 

edges  of  mover  blades 69 

Heating      machine      for      hardening 

cones    and    shells 70 

Heating  machine  for  small   parts.  .      73 
Heating  machine  for  tempering  and 

coloring  steel    78 

Heating     machine     with     revolving 

trays     71 

Heating   steel   for   forging 18 

Heating    slowly    to    a    spring    tem- 
per      158 

Heating  steel,  temperature  tell-tales 

for    159 

Heating  the  annealing  ovens 47 

Heating  the   steel    too   quickly 99 


Heating    the    die 168 

Heating     unequally     159 

Heats,  welding 175 

Heavy   work,   hardening  extra 131 

Heavy  oil    108 

Heavy   springs,   hardening 120 

Highest   carbon   steel,    not   desirable 

to   use    103 

High-carbon    steels,    the    treatment 

of    15 

High-grade   steel   forgings   in   Amer- 
ica       170 

High-grade  steel  in  the  smith's  fire.  160 

Hinged   plates   for   hardening   saws.  10S 
History    of    the    change    from    iron 
forgings     to     high-grade     steel 

forgings  in  America    177 

Hob,    how    to    grind    a    wormwheel 

hob     241 

Hobs    or    master    taps 102 

Hobson's    steel     18 

Hollow    forgings,    oil-tempered    and 

annealed    180 

Hollow   ingot    180 

Hollow  mills,   how  to   temper    ....  153 

Hollow  mills,  hardening 153 

Hot   water,   hardening   in 117 

Hot   water,   tempering  springs   in. .  120 

Horse    power    of    belts 225 

Howe-Brown  steel   18 

How   to   caseharden,    color   and   an- 
neal with  granulated  raw  bone  130 
How   to   caseharden   malleable   iron.  133 
How    to    caseharden    rolls,    leaving 

tenons   soft   for   riveting 132 

How  to  dump  the  work 135 

How   to   grind   a   die    blank   to    the 

required  angle    248 

How    to   grind    milling   cutters    and 
metal  slitting  saws  straight  or 

concave    

How    to   grind    a    hardened    drilling 

jig   bushing    

I  low  to  grind  a  slitting  knife  with 

bevel    edges     245 

How  to  grind  a  wormwheel  hob.  .  .  241 

How  to  grind  a  taper  spindle 244 

How  to  harden  a  long  punch  so  as 

to  prevent  warping  ". 165 

How  to  grind  a  large  ring  die....  164 

How  to  heat  for  annealing 37 

How  to  restore  overheated  steel .  .  .  184 
How    to    thoroughly    anneal    high- 
grade  tool  steel  parts    37 

How  to  use  old  bone   138 

How  hollow  shafts  are  forged 179 

Hubbard's  granulated   raw  bone . . .  130 


Illustrations  showing  various  work 
performed  on  a  different  type 
of  universal  cutter  and  tool 

grinder     257 

Imperfect  preceding  operations  ....    167 
Importance  of  having  a  good  foun- 
dation  for    drop    192 

Impossible  for  the  operator  to  be- 
come skilled  in  the  art 119 

Improper  means  for  grinding 168 

Improved      soldering     and      tinning 

acid    196 

Improvements  in  the  manufactur- 
ing and  forging  of  crucible 

cast   steel    176 

Improving  poor  steel    184 

Inception   of  the   art 187 

Increasing   the    size    of   the    reamer 

when    worn     19i 

Individual    testing  by   the   toolmak- 

ers     24 


282 


INDEX. 


Information       upon      air-hardening 

steels     113 

Information    of    value    to    practical 

men    31 

Injurious  effects  of  overheating.  .    .  18 

Injuring  the  quality  of  the  metal    .  175 

Inserted  type  of  milling  cutters.  .    .  198 

Insure    against    warping 158 

Interesting   data    114 

Internal   anvil    18i? 

Internal    grinding     246 

Internal   strains,    their   cause 175 

In    America,    high-grade    steel    forg- 

ings    176, 

In  crude  oil,  tempering  rock  drills.  120 
In       expansion      and       contraction, 

amount  of  force  exerted 33 

In     hardening,     straightening     long 

tools  which   have   warped 157 

In  hardening,  the  use  of  clay 110 

In     hardening     steel,      temperature 

tell-tales   for    use 134,  159 

In    U.    S.    table    of    different    stan- 
dards for  wire  gage  used 219 

In   welding,    substitute   for   borax..  187 

Iron,  a  casehardening  mixture  for .  .  141 
Iron     and     steel     sheets,     table     of 

weights    of    214 

Iron  and  steel,  welding  power  for.  .  183 

Iron  castings,  to  anneal 137 

Iron,   silver   or   white,   annealing.  .  .  44 

Irregular  pieces,  heating 107 


Jessop's  steel    18 

Joshua  Rose,  M.E 98 

Journal   of  the   Franklin   Institute.    113 
Journal    of    the    United    States    Ar- 
tillery         206 

Judgment  and  carefulness   in  hard- 
ening       95 

Judgment,    experience    and    percep- 
tion in  the  working  of   steel .  .      31 

K 

Kerosene,    casehardening    \yiui 197 

Kinds    of   steel    produced    in    Amer- 
ica   by    the    crucible    and    open 

hearth  process   34 

Knives,    tempering   wood-planer.  .  .  .    122 
Knowledge    and    skill    employed    in 

working    steel     95 


Labitte,  M.  j lS5 

Laboratory   experiments    182 

Lacquer   for   brass   articles . 206 

Lacquer   for   silver    206 

Large  milling  cutter,  hardening .  .  .  143 
Large  power  units  used  in  electric 

generating  stations    176 

Large  ring  dies,   how  to  harden...    164 

Large  spiral  fluted  "hob"   tap 19 

Large    tank    indispensable 162 

Large    tank    provided    with    perfor- 
ated  tray    167 

Latent     prejudice     against     hollow 

f  orgings    181 

Laving  out  work 196 

Lead   hardening  furnace    88 

Leaving  one  of  the  dies  soft 1<i3 

Length,    measure    of 211 

Liability    to    crack 101 

Liability    to    fracture 15 

Lime,  to  clean  tank  with 20 

Lineal  foot,  table  of  pounds  per.  .  .  215 
Link  Belt  Engineering  Company.  .  T13 
Lodge,  Mr.  William  '.  .  .  199 


Long    delicate    reamers 110 

Long,  flat  or  round  objects,  harden- 
ing .  .- 105 

Long  knives  sure  to   warp 123 

Long  taper  die-taps    103 

Loose  dirt,   to  clean  in 121 

Low  carbon  steel  bars,  to  anneal..  136 
juowered,    modified,    tempered,    less- 
ened       117 

Lubricant    for   cutting    225 

Lubricant  for  cutting   steel  or  iron.  225 

Lubricant  for  drilling   hard   steel .  .  196 

Lubricant  for  water  cuts    196 

Lubricant  for   working  aluminum.  .  196 

M 

Machine,     attachments     which    are 

used  on   the    256 

Machine    blacksmithing 189 

Machine,  construction  and  operation 

of   barrel   heating    77 

Machine  parts,  general  matter  rela- 
tive to  malleable  iron  48 

Machine  parts,  the  annealing  of 
malleable  castings  and  the  man- 
ufacture of  malleable  iron ....  44 

Machine    reaming    201 

Machine    screw    taps,    table    of    tap 

drills    for     218 

Machine   steel   casehardened   tools.  .    129 
Machines,    processes  and  tools  used 

in    the   art    187 

Machinery  steel  cutting  tools 129 

Making  a  tap  or  reamer  cut  larger 

than    itself 195 

Making  welding  heats,  coke  for.  .  .  .    100 

Malleable    department     46 

Malleable  iron,  how  to  caseharden.  .    133 

Manipulated    in    the   fire 97 

Marking  each  separate  brand 14 

Master   Mechanics'   and   Master  Car 

Builders'    Association    177 

Material     possessing     a     very     high 

elastic    limit     181 

Maximum    efficiency     113,116 

Measure   of    length    211 

Measure  of  surface 21 1 

Measure  of  volume  and  capacity.  .  .   211 

Measure   of  weight 211 

Measuring  expansion  and  contrac- 
tion    32 

Medimum  cuts  and  feeds  and  coarse 

thread   cutting    27 

Melting  points,   table   of 124 

Melting    pots    90 

Metal  is  improving  by  forging 191 

Metal  pattern  shop  of  malleable  de- 
partment    49 

Metal  saws,  to  harden   108 

Metal  slitting  saws   154 

Metal  to  expand  in  cooling 206 

Method,  advantages  of  the 147 

Metric  and  IT.  S.  measures.. 211 

M>ssrs.  Taylor  and  White 113 

Diddle  softer  than  the  outside 99 

Mild  steel  chips  and  borax 163 

Mill  picks,  bath  for  hardening 121 

Mill  picks,  hardening  and  tempering  121 
^nil  picks,  tempering  of  cast  steel .   121 

*nil  picks,  to  temper 121 

Mill    should    be    inverted 153 

Millimeters   and    fractions    of   milli- 
meters, decimal  eouivalents.  .  ^08 

Millimeters    of,    table 208 

Milliner  cutters    hardening  V  shaned  152 
Milling  wrought  iron  or  steel,  lubri- 
cant   for    204 

Mininsr  and   Scientific   Press .    i?0 

*Vfistakes  and  accidents    24 

Miscellaneous    21 1 


INDEX. 


283 


Mixture  composed  of  equal  parts  of 

charred  leather  and  charcoal.  .  180 

Moderate   cost,   testing  at  a  .......  24 

Moisture    in    crucible  .............  107 

Molecules  assume  the  most  stable 

position     ...................  119 

Molecule  motion   .................  32 

More  steam  than  hole  can  contain.  .  Io4 

Most  generally  used  bath  .........  96 

Most  satisfactory  results   .........  119 

Moving  laterally  when  quenching..  102 
Mower  blades,  heating  machine  for 

hardening  the  edges  of  .......  69 

Moxon's  method  of  casehardening.  .  lil 

Mr.    Charles    Day  ................  113 

Mr.  P.  A.  Pratt  ..................  41 

Mr.   William   Lodge  ...............  199 

Mr.    Robert    Leith  ................  48 

Much  depands  on  even  heating.  .  .  .  143 

Muffle    furnaces    .................  93 

Multiple  or  inserted  cutter  heads.  .  204 

Muffle    regular    sizes    of  ...........  93 

"Mushet"    steel    .................  115 

Museum  of  Arts  and  Trades  in 

Paris    ......................  33 


S 

Necessary    dies    to    produce    special 

drop  forgings    ...............    188 

Necessary    precautions  ............    109 

'Nerve,"    "gall"    and  .............      95 

Nicely    coppered    surface  ..........    196 

Nickel  steel  forgings,  government 

use   of    .....................    194 

No   nossibilitv  of  overdrawing  .....    119 

No  provision  made  for  water  cool- 

ing   ........................    168 

Not  necessary  to  brighten  after  the 

operation     ..................    119 

Not  indicative  of  a  uniform  degree 

of    hardness    ................    118 

Number  of  revolutions  a  drill  should 

run    .......  .................   202 


O 

Object  of  Messrs.  Taylor  and  White  113 
Obtaining    colors     with    granulated 

raw    bone 134 

Of  parts  of  an   inch,   table  decimal 

equivalents     209 

Of  solids,  table  of  melting  points..    124 
O.    II.    and   Bessemer   machine   steel     42 

Oil   bath    96 

Oil  cools  without  cracking 123 

Oil    commencing    to    smoke    a    suffi- 
cient   indication     151 

Oil  serves  as  an  indicator  of  desired 

temper    151 

Oil    tempering   furnaces 81 

Oil,    tempering    in 117 

Old  bone,  how  to  use 133 

Old  files,  to  temper 160 

Old   Point   Comfort 178 

One    of    the    largest    producers    of 

steel  in  the  world 35 

Only       carbonized       portions       will 

harden    132 

Open  and   crystallized   fracture....      17 
Open  fire,  annealing  steel  in  the.  .  .      43 

Open  fire  and  color  test 119 

Open  fire,  hardening  milling  cutters 

in  the 143 

Operation  of  the  process 116 

Operator   not    familiar   with    nature 

of   the   steel ]  67 

Ordering  steel   for   dies 14 

Ordinary  method  for  tempering  mill- 
ing cutters    147 


Ordinary    twist    drill    with    female 

center     199 

Ordinary  way  of  getting  rid  of  the 

center     179 

Outfit  for  fine  grain  casehardening.    129 
Output  of  malleable  department...      48 

Outside   very    hard    151 

Overheated    steel,    to    restore 184 

Overheating  when  forging 18 


Pack  in  good  animal  carbon 142 

Packing  and  heating  the  work....  129 
Packing  in  iron  box  in  powdered 

charcoal  103 

Packing  the  work  143 

Pameacha  raw  bone  133 

Parts  produced  by  drop  forging.  . .  .  187 
Parts  subject  to  pressure,  wear  or 

concussion  139 

Parts  with  thin  sides  or  edges ....  97 

Paste,  casehardening  141 

Perforated  iron  pan 159 

Persistent  exposure  of  fallacies ....  182 
Phosphorus  makes  steel  brittle ....  130 
Pieces  coming  out  free  from  cracks.  95 
Pieces  with  holes  running  part  way 

through  them  154 

Piercing  punches,  hardening 104 

Placing  the  die  in  an  inclined  posi- 
tion    164 

Plain  or  formed  milling  cutters.  . .  .  143 

Plain  water  96 

Planer  knife,  tempering  wood 122 

Playing  card  dies  173 

Plunging  overheated  steel  into 

water  95 

Plunging  into  petroleum 198 

Pointer  184 

Points  to  be  remembered 52 

Polished  parts,  casehardening 141 

Polished  steel  surfaces,  coppering  196 

Polishing  for  tempering 147 

Poor  material  cannot  be  used 191 

Porter,  Mr.  H.  F.  j 90 

I'otassium,  casehardening  with 

cyanide  of 137 

Pots,  different  methods  of  packing 

castings  in  45 

Pots,  melting  99 

Powdered  charcoal  and  coke!'.  !  104 

Powdered  cyanide 107 

Power  of  burnt  bones 142 

Practical  speeds  at  which  tools  can 

be  run  115 

Practice  of  the  best  shops 31 

Practice,  reamer  199 

Pratt  &  Whitney 41 

Prejudice  against  steel  generally..  178 

Preparation  of  the  work 44 

Press  tools,  use  of  machinery  steel 

for  129 

Press  tools,  the  use  of  machine 

steel  for  129 

Prevent  blowing  when  pouring  in 

damp  boxes 106 

Prevent  carbonization  of  stock....  132 

Prevent  cracking  157 

Prevent  warping,  hardening  so  as 

to  158 

Prevent  warping,  hardening  a  long 

punch  so  as  to 165 

Preventing  unequal  expansion 107 

Process  requires  a  good  quality  of 

steel  ....?...  19T 

Process  very  much  simplified 117 

Process  which  does  not  reduce  the 

hardness  of  steel 117 

Processes  and  conditions  in  con- 
nection with  each  other 31 


284 


INDEX. 


Processes,  kind  of  steel  produced  in 
America    by    the    crucible    and 

open  hearth    34 

Processes  which  tend  to  reduce  the 

hardness   of   steel    117 

Products  of  the  drop  forging  indus- 
try        187 

Prof.  E.  Wilson    197 

Prominent  features    227 

Proper    equipment    for    steel    work- 
ing          52 

Proper     equipment     for     hardening 

and   tempering    52 

Proper    facilities    for     steel     treat- 
ment           50 

Proper  heat  for  plunging  the  steel.    121 

Proportion  of  carbon I/ 

Proportion  of  soft  core    158 

Protecting    exposed    parts 98 

Protecting   teeth    from   decarboniza- 

tion     109 

Prussiate    about    to    decompose    and 

dissipate     142 

Pulverized   charcoal    133 

Pumping  oil  to  annealing  ovens.  ...  4< 
Punch  or  die  blank,  re-annealing  a.  170 
Punch,  tempering  a  combination 

cutting   and    drawing 173 

Punches  and  dies,  soft  or  hard.  .  .  .  163 
Punches  for  perforating- heavy  stock  170 

Punches,  tempering  small    171 

Punching  or  shearing  heavy  metals  163 
Putting  the  steel  in  the  bath,  man- 
ner   of     95 


Quenching  bath    96 

Quenching    for    hardening 100 

Quenching  in  salt   water 161 

Quenching  in  a  large  tank  of  water  173 

Quick  methods  for  softening  steel.  .  43 

Quoted  reports  of  tests 113 


R 

Radial  type  of  milling  cutter....  154 

"Railway  Review" 140 

Rails,  casehardening  the  ends  of 

steel  140 

Rake  of  forming  tools  204 

Rapid  cooling  of  the  forging 14 

Rapid  extraction  heat 101 

Rapid  method  of  annealing  special 

steel  116 

Rare  for  an  oil-tempered  drill  to 

break  120 

Raw  linseed  oil  96 

Raw  potato,  sticking  in  a 158 

Raw  weld  joint  14 

Real  knowledge  93 

Reamer,  babbitt  201 

Reamer,  evenly  spaced  will  chatter.  199 

Reamer,  expansion  201 

Reamer,  "floating" 201 

Reamer  for  iron 201 

Reamer  for  screw  machine 20° 

Reamer  for  brass 200 

Reamer  for  steel 201 

Reamer,  formed  or  curving 20? 

Reamer,  hand ?°o 

Reamer,  "home  made" 1  °0 

Reamer,  large  taper 20^ 

Reamer,  Rose  20*> 

Reamer,  speed  for 202 

Reamer,  square  201 

Reamer,  taper,  with  three  blades .  .  199 

Reamer,  too  much  clearance  on.  ...  200 
Reamer,  when  worn,  to  increase 

the   size  of 195 


|  Reamers  and  reaming 200 

Reaming  a  long  straight  hole 201 

|  Reamers,  hardening  taper  109 

Reamers,  hardening  long  taper.  .  .  .  1O9 

Reaming,  reamers  and 200 

Reannealing  a  punch,  or  a  die 

blank  170 

Reannealing  tap  blanks 42 

Regular  sizes  of  muffle 93 

Relation  which  the  elastic  limit 

bears  to  the  tensile  strength.  .  11)4 

Red  hot  lead,  heating  in 106 

Reduction  of  strength  98 

Removing  large  amounts  of  stock..  117 
Removing  technical  objections  to 

the  color  test  117 

Removing  rust  from  polished  steel 

or  iron 206 

Responsibility  for  •  bad  work  in 

hardening  159 

Responsible  for  bad  work 95 

Results  in  steel  when  hardened  at 

a  given  temperature  18 

Required  angle,  how  to  grind  a  die 

b'ank  to  the 248 

Return  to  its  elastic  state 157 

Ring  gages,  hardening 156 

Riveting,  how  to  caseharden,  rolls 

leaving  tenons  soft  for 132 

Robert  Leith,  Mr 48 

Rock  drills,  tempering  120 

Rogers,  Admiral  John 178 

Rogers  &  Hubbard  Company 130 

Rough-down  blanks  for  long  tools.  .  103 

Rough  test  on  cast  iron 114 

Round  dies,  hardening  thick 172 

Round  dies,  hardening  the  walls  of.  169 
Round  thread  dies,  hardening  and 

tempering  111 

Rose,  M.  E.,  Joshua 98 

Rosin  on  the  blacksmith's  forge.  .  .  1S4 

Rules  for  calculating  speed.... 27.  1!)."> 

Rust  joints,  cement  20(> 


S 

Salt,  heating  in  melted 96 

Sal-soda  and  borax  in  water 106 

Sanderson's  steel 18 

Sand  bath,  ^empering  in  the 117 

Saving  of  46  per  cent 114 

Schneider    &    Co.,    of    Le    Creusot, 

France    179 

Scientific    American    Supplement.  .  .  98 
Screw     and     dowel     holes     plugged 

with   fire   clay    166 

Screw  head  slotting  saws 159 

Screw;  threads,  U.  S.  S 220 

Securing  the  best  results  from  steel  23 

Secretary  of  the  Navy 178 

Sectional  casehardening,   accurate.  .  139 

Sections  and  shapes  of  file  steel,  16,  IT 

Segregation    and    piping 180 

Selection  and   identification  of  steel  13 
Selection   of   brands    and    grades   of 

steel    13 

Selection  of  steel   of  uniform   dual- 
ity       13 

Self -hardening   brands    18 

Self-hardening  steel  cutting  tools.  .  27 
Self-hardening   steels,    treatment    of 

high-speed    20 

Servicable  slack  tub    121 

Set  of  hardened  and  tempered  turn- 
ing tools    22 

Set    of   self-hardening   steel   cutting 

tools   25 

Setting  the  grain  of  steel  finer....  159 
Setting  the   fine   grain   permanently  180 
Severe  usage  in  the  nature  of  alter- 
nating   stresses    181 


INDEX. 


Shear    blades,    gas    forge    for    knife 

and   64 

Shell   end   mills    147 

Shells,  heating  machine  for  temper- 
ing and   coloring    70 

Shells,    heating  machines   for   hard- 
ening,   cones    and 70 

Shrinkage   in  soft  steel    42 

Skill,    experience    and    judgment    in 

hardening     118 

Soliciting    orders    tor    Hollow    forg- 

ings     181 

Slowly   cooling  the  inside 150 

Slower    the    temper    is    drawn    the 

tougher  the  steel   119 

Small  articles  of  even  thickness.  .  .  107 

Small   and   medium   size   springs...  120 

Small  fagots  of  wrought  iron 179 

Small    flat    springs    161 

Small  iron  parts,  to  caseharden.  .  .  .  141 

Small  iron  parts    141 

Small  parts,  annealing  box  for.  .  .  .  39 

Small  punches,   steel  for    14 

Small  punches  for  thin  stock 166 

Small  punches,  tempering    171 

Small    saws,    hardening    108 

Small  spiral  springs    161 

Small  taps,  hobs,  etc.,  how  to  tem- 
per      160 

Small   work,  gas  forge  for 59 

Smallest    sectional    area 98 

Smoke  coming  from  all  parts  of  the 

steel    151 

Soap  or  oil  in  water 20 

Society  of  Arts    197 

Soft    machine    steel    almost    worth- 
less       42 

Soft  spots  after  hardening 104 

Soft  spots  in  dies  after  hardening.  .  1G2 

Softening  steel,  quick  methods  for.  .  43 

Solder   for   aluminum 197 

Soldering   205 

Solid  core  of  lire  brick 180 

Solids,    melting   points   of    125 

Solution  to  protect  steel  from  fire.  .  106 
Solution,     %    opera    oil,     y2    neat's 

foot  oil,   one   ounce   rosin 120 

Solutions  are  used  to  some  extent..  143 

Solutions,  hardening  in 106 

Solutions,    tempering     124 

Source    of     annoyance    often    over- 
looked       154 

Spacing   entirely   too   close 199 

Special    brands    of    steel    are    pro- 
ducible       118 

Special    drop    forgings    190 

Special  end  mill    147 

Special    forming    cutter     146 

Special    instructions    110 

Special    instructions    for    hardening 

and  tempering    110 

Special   methods,    tempering  by....  117 

Special    milling   cutter    '.  .  147 

Speeds    for    cutting   tools    27 

Sperm    oil     96 

Spiral  springs,  tempering  small....  120 

Spoiling   steel    by    overheating 41 

Spring  chucks,   hardening  and   tem- 
pering   collet    112 

Spring  temper,  heating  slowly  to  a  1f»8 

Springs,   to   weld   buggy 184 

Spring  threading  die 96 

Springs,    blazing   off 120 

Springs,    bluing    ifil 

Special   hardening  and   tempering.  .  161 
Square  and  hexagon   steel,   table  of 

weights  and  areas  of  round  and  212 

Stalwart   champion   of  steel 17S 

Square  reamer    201 

Standard    brands    of    self-hardening 

steel,   experiments  with 115 


Standard   pipe    taps,    table    of   sizes 

of  drills  for    ^18 

Standards     for     wire    gage     in    the 

United    States    219 

Standard    screw    threads,    table    of 

United  States   220 

Standard  thread  formulas  for  sharp 
V  thread,  United  States  stand- 
ard Whitworth  thread  221 

Standard  twist  drill  grinding  gage.    202 

Stay-bolt   taps    103 

Steam  can  escape  and  water  enter.  154 
Steel,  annealing  a  small  quantity  of  43 

Steel    annealed    die    and    tool 21 

Steel   bars,   annealing  low  carbon.  .    136 

Steel,  a  good  welding  flux  for 175 

Steel,  cutting  and  durability  qual- 
ities of 30 

Steel,   composition   to   toughen 184 

Steel,  compound  for  welding 183 

Steel      cutting      rings      welded      to 

wrought   iron    plate    174 

Steel,     different     quenching     baths, 

their  effect  on    96 

Steel  die  forgings    14 

Steel  forgings  intelligently  pro- 
duced   179 

Steel  for  small  reamers,  taps,  small 

punches,  etc 14 

Steel    for    different    purposes 14 

Steel  for  small  punches 14 

Steel  for  tools  which  require  to  be 

forged     176 

Steel,    general    directions   and   rules 

for    the    hardening    of 97 

Steel,  how  to  restore  overheated.  .  .    184 

Steel  in  its  softened  condition 36 

Steel,  judgment,  experience  and  per- 
ception in  the  working  of  ....  31 

Steel    of   special    composition 115 

Steel   of   a   brand   which   experience 

has   taught   to   be   uniform....    118 
Steel  of  different  carbon  percentage  118 
Steel   parts,   how  to  thoroughly  an- 
neal high-grade  tool    37 

Steel  rails,  casehardening  ends  of.  .  140 
Steel,  selection  and  identification  of  13 

Steel,   the  grain  of    23 

Steel,  the  heating  and  cooling  of .  .  .  50 
Steel,  treatment  of  air-hardening.  21 
Steel,  treatment  of  annealed  die  and 

tool     21 

Steel    unevenly    heated 168 

Steel  worked  at  a  low  red  heat.  .  .  .  159 
Steel,  to  distinguish  wrought  iron 

and    cast    iron    from 197 

Steel,  to  blue  without  heating 197 

Steel,  to  remove  scale  from 206 

Sticking,    mixture   to    prevent    lead 

from     1 0S 

Straight   cvlindrical    pieces    102 

Straightening  between  lathe  centers  157 
Straightening  hardened  pieces  that 

have   warned    157 

Straightening  long   tools   that   have 

warped   in   hardening 121 

Straightening  on  anvil  with  ham- 
mer   1 57 

Straightening  on  a  block  of  wood.  .    1  ~7 

Straightening    while    cold    103 

Straightening  while  hot   103 

Strain  occasioned  bv  ranid  cooling.  .    180 

Strains    in    manufacture    96 

Stream  of  water  strikinsr  the  work     95 

Strength    of    hollow    forgings 18O 

Stretching  the  chnins   79 

Striping  with  different  color  nalnt.  14 
Strong  brine  for  the  hardening 

fluid 172 

stronsr   brine,    ouenchiner    in 96 

Stroner   close-grained    backing 130 


286 


INDEX. 


Strong  jet  of  water  in  quenching.  .  20 

Stubs  steel    166 

Styrian  steel   18 

Substances  used  to  hold  the  grains.  266 

Substances    which    open    the   grain .  129 

Substitute  for  borax  in   welding.  .  .  187 

Successful   hardening    38 

Successful   metal   working 20 

Sudden  heat  and  a  cold  blast  of  air  168 
Suitable   specimen   for   experimental 

purposes     15 

Suitable  tempers  for,  table  of 127 

Sulphur,  little  as  possible 106 

Supervision     of      chemists,      metal- 
lurgists,   physicists,   and  micro- 

scopists    179 

Surface,  measure  of '. 211 

Surface      of      lead      covered      with 

broken    charcoal     107 

Surface  scale    96 

Surfaces,  coppering  polished  steel .  .  196 

Surfaces,   decarbonized  steel 24 

Surplus   metal   thrown   out   between 

the  dies  while   working 190 

Sword  blades,   straightening 157 


Table  of  articles  made  from  crucible 
steel,  giving  about  percentage 
of  carbon  they  should  contain.  269 

Table  of  average  cutting  speeds  for 

drills  223 

Table  of  cutting  speeds   224 

Table  of  decimal  equivalents  of 
millimeters  and  fractions  of 
millimeters  208 

Table  of  decimal  constants  for  find- 
ing diameter  at  bottom  of 
thread  210 

Table  of  different  standard  for  wire 

gage  used  in  the  U.  S 219 

Table  of  decimal  equivalents  of 

parts  of  an  inch  209 

Table  of  expansion  from  32  degrees 

P.  to  212  degrees  F 35 

Table  of  English  or  America  (U.  S.) 

equivalent  measures  211 

Table  of  melting  points  of  solids..   211 

Table  of  suitable  temperatures  of 
annealing,  working  and  harden- 
ing    127 

Table  of  suitable  temperatures  for 
casehardening  core,  ovens,  dry- 
ing kilns,  baking  channels  and 
vulcanizing  rubber  128 

Table  of  sizes  of  drills  for  stand- 
ard pipe  taps  ' 218 

Table  of  thread  narts    122 

Table  of  tempers  to  which  tools 

should  be  drawn 125 

Table  of  temper  colors  of  steel ....    128 

Table  of  tap  drills  for  machine 

screw  taps  218 

Table  of  United  States  standard 

screw  threads  . 220 

Table  of  weights  and  areas  of 

round,  square  and  hexigon  steel  212 

Table  of  weights  of  iron  and  steel 

sheets 214 

Table  of  weights  of  square  and 
round  bars  of  wrought  iron  in 
pounds  per  lineal  foot 215 

Taking  from  the  water  too  soon.  .  .    101 

Tap  blanks,   reannealing    42 

Tap  drills  for  machine  screw 

threads  21 8 

Tap  steel,  the  annealing  of 41 

Taper   mill    147 

Taper  of  twist  drills  for  clearance.    198 

Taper  reamer  with  three  blades ....    199 


Taylor-White    process    for    treating 

steel    ....    113 

Tell-tale,  using  the 134 

Temper  colors  proof  of   equality   in 

degree  of  heat  only   118 

Temper  drawn   at  leisure    143 

Temper  when  due  to  a  second  opera- 
tion    118 

Tempers    to    which    steel    should   be 

drawn,  table  of    125 

Tempering     117 

Tempering  at  special  colors Ill 

Tempering    a    combination     cutting 

and  drawing   punch    173 

Tempering      flat     drills     for      hard 

stock     160 

Tempering  in   the   charcoal  fire....    122 

Tempering    in   oil    119 

Tempering  in  the  sand  bath 119 

Tempering    process    which    will    de- 
termine accurately  first  heat..    118 
Tempering  rock  drills  in  crude  oil .  .    120 

Tempering  small  punches    171 

Tempering  small   spiral  springs....    120 
Tempering  swords  and  cutlasses...    123 

Tempering  special  tools    us 

Tempering  solutions    124 

Tempering    thin    articles 122 

Tempering  wood  planer  knives 122 

Temperatures  at   which   solids   melt  124 
Temperatures    tell-tales    for    use    in 

hardening  steel    159 

Tendency   to   crack    97 

Tendency  to  refine 103 

Tendency   of  steel   to   crack   around 

the    holes     166 

Tenons   soft   for   riveting  to  harden 

rods  leaving   132 

Test  made  at  the  Government  test- 
ing bureau  182 

Testing  the  chain   to  insure  proper 

length     49 

Testing  for  hardness  with  a  file ...      24 

Testing  for   hardness    24 

Testing  for  heat    103 

Testing  for  toughness    24 

Testing  for  trueness   103 

Testing    steel,     economy    in    before 

using     25 

Testing  tool  steel    23 

Tests      of      steel      tinder      repeated 

stresses    182 

Texture    restored    by    hammering   or 

rolling    fo...    175 

That     have     warped,     straightened 

hardened    pieces     157 

The  annealing  of  tap  steel 41 

The  annealing  of  malleable  cast- 
ings and  the  manufacture  of 
malleable  iron  machine  parts.  44 

The  acme  standard  thread 222 

The  amount  of  force  exerted  in  ex- 
pansion and  contraction  33 

The  best  steel  for  tools 23 

The  bath    96  to  135 

The  castings,  the  foundry  and  prep- 
aration of 44 

The  difference,  tough  steel  and  hard 

steel    93 

The  effect  of  slow  heating  and  tem- 
pering    no 

The  effect  of  water  annealing 40 

The   emery   wheel    used   as   a   metal 

slitting   saw    249 

The  first  effect  of  heat 31 

The  foundry  and  pi-eparation  of  the 

castings 44 

The  grain  of  steel    23 

The    hardening    and    tempering    of 

preps     tools     162 

The  hardening  fire  and  the  heat  ...      99 


INDEX. 


287 


The  hardening  of  long  slender 
tools  

The  heating  and  cooling  of  steel.  .  . 

The  location  of  the  heating  furnace 

The  proper  heat  for  annealing .... 

The  slender  tools,  hardening  long.  . 

The  second  effect  of  heat 

The   terms   defined    

The  treatment  and  working  of  well 
known  brands  of  tool  steel.  .  . 

The  treatment  of  hign-carbon  steels 

The  Taylor-White  process  for  treat- 
ing steel  

The  use  of  clay  in  hardening 

The  use  of  gas  blast  furnaces  and 
heating  machine  

The  use  of  machine  steel  for  press 
tools  

The  work,  how  to  dump 

Their  cause,   crack   in  dies 

Their   use   of   emery    wheels 

Their  use,  gas  blast  forges 

Thick    cast    iron    plates 

Thick  round  dies,  hardening 

Thick  scale  results  from  high  tem- 
perature   

Thin  and  delicate  parts,  hardening. 

Thin  edges  and  exposed  parts,  heat- 
ing the  

Thin  parts,  hardening  small  parts 
and  long  

Thread  dies,  hardening  and  temper- 
ing round  

Thread  parts,  table  of 

Thrust  bearing  rings,  hardening 
five-inch  

Time  required  to  machine  a  given 
surface  

Time    saved    

Tinning  acid,  improved  soldering 
and  

Tires,   fastening  to   wheels 

To  anneal  doubtful  steel   

To  a  blue,  to  draw  small  steel  parts 

To  blue  steel  without  heating 

To   caseharden   without   colors 

To  caseharden  small  iron  parts.  .  .  . 

To  caseharden  with  charcoal 

To  caseharden  cast  iron    

To  distinguish  wrought  iron  and 
cast  iron  from  steel 

To  draw  small  steel  parts  to  a  blue 

To  distinguish  the  grades    

To  heat  and  cool  steel  properly.  .  .  . 

To  make  edge  tools  from  cast  steel 
and  iron  

To  produce  fine  grain  casehardened 
machine  steel  parts  

To  prevent  rust 

To  remove  scale  from  steel 

To  temper  gravers    

To  temper  old  files 

To   weld  cast   iron    

To  weld  buggy  springs    

Too   high   welding  heat •• 

Tool  facilities  not  up-to-date.  ..... 

Tool  holders  and  tools,  their  use. 28, 

Tool  holders  and  tools 

Tool  steel,  testing 

Tool  steel,  the  treatment  and  work- 
ing of  well-known  brands  of.  . 

Tools  carrying  a  cutting  edge 

Tools  circular  forming 

Tools   or  parts  with  fine  projections 

Tools  used  for  bending  and  form- 
ing   

Tools,  the  best  steel  for   

Tools,    working    steel    for    

Tools,    tool    holders    and 

Tough  steel  and  hard  steel,  the  dif- 
ference   


103 
50 
52 
37 

103 
34 


113 

110 


129 
135 
167 
266 
54 
159 
172 

22 
104 

18 
104 

111 

222 

131 

30 
24 

196 

33 

43 

161 

179 

130 

141 

141 

195 

197 

161 

23 

50 

183 

139 

196 

206 

160 

160 

183 

184 

14 

113 

29 

25 

23 

18 

18 

203 

108 

130 
23 

ir>o 

25 
93 


Tougher  effect  to  steel  than  bone .  . 

Toughness,    testing    for 

Tracy,   Mr.   B.   E 

Trays,  heating  machine  with  revolv- 
ing   

Treatment,  air-hardening  steel 

Treatment,  annealed  die  and  tool 
steel  

Treatment  of  high-speed  self-hard- 
ening steels  

Treating  steel,  Taylor-White  pro- 
cess for  

Tremendous   strains    

Trimming  dies 

Tumbling  instead  of  pickling  drop 
forgings  

Turn  the  bulge  out 

Twirling    around    rapidly 

Twist    drills,    grinding     

Twisting  of  long  tools  in  harden- 
ing  

Two  cooling  surfaces    

Two  ways  of  making  a  forging  hol- 
low   

Types   of   milling   centers    


U 


it 


Understood,     casehardening     as 

should  be  

Unequal   expansion    

Uneven  contraction  provided  for.  .  . 

Uneven  heating,   distortion   through 

Uniform  hardness  and  temper 

Uniformity  of  results  attained   .... 

United  States  Government 

United  States  War  Department.  .  .  . 

United  States  weights  and  measures 

United  States  measures  of  lengths. 

United  States  measures  of  surface. 

United  States  measures  of  volume. 

United  States  measures  of  weights. 

Universal     adoption     of     the     ther- 
mometer   test    

Unnecessary      expense      in      testing 
steel    

Upward     flow     of     water     through 
article    

Use  for  which  forging  are  intended 

Use  of  milling:  cutters   

Use  of  various  kinds  of  baths 

Using   a   punch   and   die   which   are 
both  hard 

Using  a  small  narrow  broach 

Using  a  soft  punch  and  a  hard  die 

Using,  economy  in  testing  steel   be- 
fore      

Using  scrap  steel  for  malleable  iron 

Using  the  tell-tale 

Usual    methods    of    hardening    air- 
hardening  steel    


130 
24 

178 

71 
21 

21 


113 
177 
190 

191 
103 
146 

202 

158 
180 

179 
145 


142 

32 

168 

95 

106 

114 

23 

108 

217 

217 

217 

217 

217 

117 
24 

112 

191 

154 

96 

163 
112 
163 

24 

48 

134 

113 


Vapors  generated  in  the  bath 154 

Variation  from  a  vertical  position.  .  109 

Variation  of  carbon,  effects  of   ....  114 

Various    defects    in    ingots    1 

Very   deep   casehardening    140 

Very    little    external    heat    required 

to   draw   it 151 

Vessels  of  proper   wiath 123 

Very  small   piercing  punches,   hard- 
ening      171 

Very  small  punches,   hardening....  171 

Vitrified    emery    wheel 265 

W 

Walter  A.  Wood  Mowing  and  Reap- 
ing Machine  Company 44 


288 


INDEX. 


Warming  the  work  up  to  a  blue.  .  .    153 
Warped,  straightening  pieces  which 

have    ... 121 

Warping,    hardening    a    long    punch 

so  as  to  prevent    165 

Warping,   hardening  very   thin  tools 

so  as  to  prevent 158 

Warping  of  long  punches  in  harden- 
ing     171 

Warping,    of    long   tools   in   harden- 
ing         171 

Warping,   the   weaker   parts    101 

Washington     178 

Water  and  oil,   hardening  and  tem- 
pering   milling   cutters    in 147 

Water,    annealing    39 

Water,  cuts,  lubricant  for 196 

Water  for  cooling   101 

Water,   kept  at  a  boiling  point....    168 
Weights  and  areas  of  round,  square 

and    hexagon    steel 212,   213 

Weights,    measure    of 211 

Weight   of  cast   iron,   wrought   iron, 

steel,  copper  and  bronze.....  207 
Weights  of  iron  and  steel  sheets.  .  .  214 
Weights  of  square  and  round  bars 

of   wrought    iron    215 

Weights      and      measures,       United 

States     217 

Weld  which  will  not  buckle  or  sepa- 
rate in   hardening    163 

Welding  composition  for  cast  steel.  .    183 

Welding  cast  iron   183 

Welding,   flux  for   soldering  and.  .  .    187 

Welding   heats    175 

Welding    heat    for    steel    should    be 

higher  than  that  for  iron.  ...  175 
Welding  powder  for  iron  and  steel.  183 
Welding  steel  to  steel  or  steel  to 

iron     175 

Wetting  the  fracture    23 

Wheels,      approximate     speeds      for 

emery    and    polishing 267 

When  a    muffle   is   used 164 

When      hardening,      dipping      fluted 

reamers    .  157 


When      hardening,      dipping      half 

round  or  "gun"  reamers 105 

When  hardening,  dipping  small 

tools  156 

When  the  proper  lieat  has  been 

reached  , .  .  153 

When  worn,  increasing  the  size  of 

the  reamer  195 

Whit  worth,  Sir  Joseph  178 

Why  special  instructions  are  given.  Ill 

Williams  &  Co.,  J.  H 180 

Wilson,  Prof.  E 197 

Without  colors,  to  caseharden 130 

Without  heating,  to  blue  steel 197 

"Woodworker"  122 

Work,  cleaning  the  135 

Work,  combination  gas  furnace  for 

general  machine  shop 54 

Work,  hardening  draw-bridge  disc 

and  similar 131 

Work,  laying  out  196 

Work,  packing  and  heating  the.  .  .  .  129 

Work,  preparation  of  the  134 

Work,  packing  the  45 

Work,  to  dump  the 135 

Work,  to  pack  the  134 

Work  with  deep  recesses . 93 

Working  and  hardening,  suitable 

temperature        of        annealing, 

table  of  127 

Working  Capital  steel  21 

Working  up  and  down  rapidly....  154 

Working  steel  for  tools 159 

World's  Fair,  Chicago 181 

Worry,  vexation  and  poor  work.  .  .  .  17(5 

Wrenches,  drop  forged  1 89 

Wrong,  to  apply  the  term  "temper," 

when  it  is 117 

Wrought  iron  for  crossheads,  and 

crank    pins    181 


Zinc,  solder  for   187 

Zinc,  to  color  or  coat    206 


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Reagan,  Jr.     Electrical   Engineers'  and  Students'  Chart  and   Hand 
Book  of  the  Brush  Arc  Light  System  : 

Illustrated.  Bound  in  Cloth,  with  Celluloid  Chart  in  Pocket.  8vo. 
Cloth  $1 . 00 

Sloane.    Electricity  Simplified. 

The  object  of  "Electricity  Simplified"  is  to  make  the  subject  as  plain 
as  possible,  and  to  show  what  the  modern  conception  of  electricity  is. 
158  Pages.  Illustrated $1 .00 

Sloane.    How  to  Become  a  Successful  Electrician : 

It  is  the  ambition  of  thousands  of  young  and  old  to  become  electrical 
engineers.  Not  every  one  is  prepared  to  spend  several  thousand  dollars 
upon  a  college  course,  even  if  the  three  or  four  years  requisite  are  at 
their  disposal.  It  is  possible  to  become  an  electrical  engineer  without 
this  sacrifice,  and  this  work  is  designed  to  tell  "How  to  Become  a 
Successful  Electrician,"  without  the  outlay  usually  spent  in  acquiring 
the  profession.  189  Pages.  Illustrated.  'Cloth ?1 .00 

Sloane.    Arithmetic  of  Electricity : 

A  Practical  Treatise  on  Electrical  Calculations  of  all'  kinds,  reduced 
to  a  series  of  rules,  all  of  the  simplest  forms,  and  involving  only  or- 
dinary arithmetic  :  each  rule  illustrated  by  one  or  more  practical  prob- 
lems, with  detailed  solution  of  each  one.  Fourth  Edition.  Illustrated. 
138  Pages.  Cloth $1 .00 


NORMAN   W.    HENLEY   &   CO.'S   PUBLICATIONS. 

Sloane.  Electric  Toy  Making,  Dynamo  Building  and  Electric  motor 
Construction  s 

This  work  treats  of  the  making  at  home  of  Electrical  Toys,  Electrical 
Apparatus,  Motors,  Dynamos  and  Instruments  in  general,  and  is  de- 
signed to  bring  within  the  reach  of  young  and  old  the  manufacture  of 
genuine  and  useful  electrical  appliances.  Third  Edition.  Fully  Illus- 
trated. 140  Pages.  Cloth $1.00 

Sloane.  Rubber  Hand  Stamps  and  the  Manipulation  of  India  Rubber: 

A  practical  treatise  on  the  manufacture  of  all  kinds  of  Rubber  ar- 
ticles. 146  Pages.  Second  Edition.  Cloth $1.00 

Sloane.    Liquid  Air  and  the  Liquefaction  of  Gases: 

Containing  the  full  theory  of  the  subject,  and  giving  the  entire  history 
of  liquefaction  of  gases,  from  the  earliest  times  to  the  present.  It 
shows  how  liquid  air  like  water-  is  carried  hundreds  of  miles  and  is 
handled  in  open  buckets.  It  tells  what  may  be  expected  from  it  in  the 
near  future.  365  Pages,  with  many  Illustrations.  Handsomely  bound 
in  Buckram.  Second  Edition  $2.50 

Sloane.    Standard  Electrical  Dictionary: 

A  practical  handbook  of  reference,  containing  definitions  of  about 
5,000  distinct  words,  terms  and  phrases.  An  entirely  New  Edition, 
brought  up  to  date  and  greatly  enlarged.  Complete,  Concise.  Con- 
venient. 682  Pages,  393  Illustrations.  Handsomely  bound  in  Cloth. 
8vo $3.00 

Usher.    The  Modern  Machinist; 

A  practical  treatise  embracing  the  most  approved  methods  of  modern 
machine-shop  practice,  and  the  applications  of  recent  improved  ap- 
pliances, tools  and  devices  for  facilitating,  duplicating  and  expediting 
the  construction  of  machines  and  their  parts.  A  new  book  from  cover 
to  cover.  Third  Edition.  257  Engravings.  322  Pages.  Cloth $2  50 

Van  Dervoort.  Modern  Machine  Shop  Tools;  Their  Construction. 
Operation  and  Manipulation,  Including-  Both  Hand  and  Ma- 
chine  Tools: 

A  new  work  treatirg  the  subject  in  a  concise  and  comprehensive  man- 
ner. A  chapter  on  Gearing  and  Belting,  covering  the  more  important 
cases,  also  the  Transmission  of  Power  by  Shafting  with  formulas  and 
examples  is  included.  This  book  is  strictly  up-to-date  and  is  the  most 
complete,  concise  and  useful  work  ever  published  on  this  subject. 
Containing  about  600  Pages  and  600  Illustrations $4.00 

\Voodworth.  Dies,  Their  Construction  and  Use  for  the  Modern 
Working  of  Sheet  Metals: 

A  treatise  upon  the  designing,  constructing  and  use  of  tools,  fix- 
tures and  devices,  together  with  the  manner  in  which  they  should  be 
used  in  the  power  press,  for  the  cheap  and  rapid  production  of  sheet 
metal  parts  and  articles.  Comprising  fundamental  designs  and  prac- 
tical points  by  which  sheet  metal  parts  may  be  produced  at  the  mini- 
mum of  cost  to  the  maximum  of  output,  together  with  special  refer- 
ence to  the  hardening  and  tempering  of  press  tools,  and  to  the  classes 
of  work  which  may  be  produced  to  the  best  advantage  by  the  use  of 
dies  in  the  power  press.  Containing  400  Pages.  500  Illustrations  ..  $3.OO 

"Woodworth.  Hardening,  Tempering,  Annealing  and  Forging  of 
Steel : 

A  new  book  containing  special  directions  for  the  successful  hardening 
and  tempering  of  all  steel  tools.  Milling  cutters,  taps,  thread  dies,  ream- 
ers, both  solid  and  shell,  hollow  mills,  punches  and  dies  and  all  kinds  of 
sheet-metal  working  tools,  shear  blades,  saws,  fine  cutlery,  and  metal- 
cutting  tools  of  all  descriptions,  as  well  as  for  all  implements  of  steel, 
both  large  and  small,  the  simplest  and  most  satisfactory  hardening  and 
tempering  processes  are  presented.  The  uses  to  which  the  leading  brands 
of  steel  may  be  adapted  ar«  concisely  presented,  and,  their  treatment  for 
Avorking  under  different  conditions  explained,  as  are  also  the  special 
methods  for  the  hardening  and  tempering  of  special  brands.  Containing 
about  320  Pages,  about  250  Illustrations $2.50 


THIS  BOOK  IS  DUE  ON  THE  LAST  DATE 
STAMPED  BELOW 


AN     INITIAL    FINE    OF    25    CENTS 

WILL  BE  ASSESSED  FOR  FAILURE  TO  RETURN 
THIS  BOOK  ON  THE  DATE  DUE.  THE  PENALTY 
WILL  INCREASE  TO  5O  CENTS  ON  THE  FOURTH 
DAY  AND  TO  $1.OO  ON  THE  SEVENTH  DAY 
OVERDUE. 


JUL    7  1933 
^e   -1 1939 


MAY  1011940 
MAR  29 1941 


SEP    9 


LD  21-50m-l,'33 


it     767^4 


I  03H4.8 


